SlideShare a Scribd company logo
1 of 238
Download to read offline
Prof. Sam Bernales, Jr.
02/10/17 03:00 AM 1
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Logic
• Logike/ Logia/ Logos
– Coined by Zeno the Stoic
• Analytics
– Prior and Posterior
– Study
– Reason
– Discourse
– Study of the
fundamental principles
which govern the true
nature of correct
reasoning or inferential
thinking.
02/10/17 03:00 AM 2
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Logic
• Science and Art of Critical
Thinking and Correct
Reasoning
• Science
– Systematized body of Logical
Truths and Principles
governing correct thinking
• Art
– Beautiful and Good reasoning
– Power to perform certain
actions guided by special
knowledge and executed with
skill
02/10/17 03:00 AM 3
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Logic in Profession
• Facilitates in organizing
ideas.
• Scientists
– Scientific Method
• Public Speaker
– Organization of Idea
• Lawyer
– Good argument to prove
position
• Household
– Planning and organizing
things in house.
02/10/17 03:00 AM 4
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Logic in Profession
• Activity
– How can I apply Logic in
my profession?
02/10/17 03:00 AM 5
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Mind Teaser
• Activity
– Abstract Reasoning
• Inverse the Triangle by
moving only 3 balls
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
6
Mind Teaser
• Activity
– Abstract Reasoning
• Connect all the spheres in
4 straight uninterupted
lines
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
7
Activity
• Abstract Reasoning
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
8
Mind Teaser
• Verbal Reasoning
– Question
• Mayroong 64 na maleta sa
eroplano na nasa
himpapawid. Kung nahulog
ang isa, ilan na lang ang
natira?
– Answer
• 63
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
9
Mind Teaser
• Verbal Reasoning
– Question
• Paano ipapasok ang
elepante sa loob ng
refrigerator sa tatlong
paraan?
– Answer
• 1. Buksan ang refrigerator
• 2. Ipasok ang elepante
• 3. Isara ang refrigerator
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
10
Mind Teaser
• Verbal Reasoning
– Question
• Paano ipapasok and giraffe
sa loob ng refrigerator sa
apat na paraan?
– Answer
• 1. Buksan ang refrigerator
• 2. Ilabas ang elepante sa
refrigerator
• 3. Ipasok ang giraffe sa loob
ng refrigerator
• 4. Isara ang refrigerator
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
11
Mind Teaser
• Verbal Reasoning
– Question
• Kaarawan ng haring leon.
Lahat ng hayop naroon
pero may nawawalang isa.
Anong hayop ito?
– Answer
• Giraffe, naiwan sa loob ng
refrigerator
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
12
Mind Teaser
• Verbal Reasoning
– Question
• Paano makakatawid sa
ilog ang isang babae nang
hindi kakainin ng mga
buwaya?
– Answer
• Tatawid lang siya kasi nasa
kaarawan ng haring leon
ang lahat ng hayop
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
13
Mind Teaser
• Verbal Reasoning
– Question
• Habang tumatawid sa ilog
ang babae, siya ay
namatay. Ano ang dahilan
ng kanyang pagkamatay?
– Answer
• Sa kanya bumagsak yung
maleta mula sa eroplano
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
14
Mind Teaser
• Verbal Reasoning
– Question
• How many dwarves are
there in the story of
Cinderella?
– Answer
• None. It was Snow White
who has seven dwarves.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
15
Mind Teaser
• Verbal Reasoning
– Question
• Which is heavier, 1kg of
Gold or 1kg of Feather?
– Answer
• There is no heavier
between the two. Both of
them weights 1kg.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
16
Mind Teaser
• Verbal Reasoning
– Question
• Inutusan ka para barilin ang
isang target. Ang sabi sayo,
kung mata tamaan mo,
saka ka babayaran.
Tinamaan mo sa noo ang
target, pero hindi ka
binayaran ng taong nag-
utos sayo. Ano ang dahilan
bakit di ka binayaran?
– Answer
• Hindi mo natamaan sa
mata ang target.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
17
Mind Teaser
• Verbal Reasoning
– Question
• May isang babae na
dumalaw sa isang puntod.
Noong tinanong siya kung
kaanu-ano niya ang nasa
puntod and sagot niya,
“Ang nanay niya ang nag-
iisang anak ng nanay ko.”
Kaano ano nya ang nasa
puntod?
– Answer
• Anak
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
18
Activity
• Verbal Reasoning
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
19
Divisions of Logic
• Formal (Form)
– Rules
– Principles
• Simple apprehension
– Grasp entity or reality
• Judgment
– Compares two ideas
based on relation
• Reasoning
– Abstraction
• Material (Matter)
– Substance of reasoning
02/10/17 03:00 AM 20
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Exempli Gratia
All senators are
politicians.
No senators are
congressmen.
X Ergo, no congressmen
are politicians.
Formally Correct
Materially Wrong
All nurses are health-
care professionals.
Some nurses are
Filipinos.
Ergo, some Filipinos are
health-care
professionals.
Formally Correct
Materially Correct
02/10/17 03:00 AM 21
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Formal Logic
• Every cat is an animal
• Every tiger is an animal
• Ergo, every tiger is cat
Formally Wrong
Materially Wrong
02/10/17 03:00 AM 22
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Formal Logic
• Every cat is animal
• Every pig is animal
• Ergo, every pig is cat.
Formally Wrong
Materially Wrong
02/10/17 03:00 AM 23
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Formal Logic
• Every animal is four
legged substance
• Some table is animal
• Ergo, every table is
four-legged substance.
Formally Correct
Materially Wrong
02/10/17 03:00 AM 24
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Structure of Logic
External Expressions/
Significations
Mental Operations
Term/
Concept
Simple Apprehension
Proposition Judgment
Syllogism/
Fallacy/ Debate
Reasoning/ Argument
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
25
Terms
• Terms
– Signs of concepts
– Instrumental
signs
– Expression of an
idea
– Thought
– Concept
– Mental
Proposition
– Mental
Argumentation
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
26
Terms according to Structure
• Simple
– Consist only one word
• Skunk
• Complex
– Consists of a group of
words that signify one
thing
• The black little cat-like
animal with the white
stripe down its back is a
skunk
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
27
Terms according to Essence
• Significant
– Signifies the quiddity
(whatness) or nature of
the thing they stand for
• Man, Dog
• Non-significant
– merely point out things
without signifying their
quiddities or nature
• This, That, Those
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
28
Terms According to Components
• Simple
– Only one feature
• Book
• Compound
– Several features
• Human Person
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
29
Terms According to Comprehension
• Concrete
– Expresses something which
has attributes that are
capable of being perceived
through the senses.
• ball, can, desk, stone
• Abstract
– expresses something as
separated from any single
object. It denotes the
general attributes of many
objects.
• When I sit next to you, my
heart beats definitely faster.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
30
Terms According to Comprehension
• Abstractive
– Creates a meaning out
of own experience
• Great experience
• Being whole
• Happiness
• Intuitive
– Requires presence of an
object
• Hot coffee
• Warmth of day
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
31
Terms According to Comprehension
• Absolute/ Privative
– No relation to other idea
• God
• Relative
– Explicit relation to other
idea
• Teacher and Student
• Master and Slave
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
32
Terms According to Comprehension
• Complete
– Expresses all features
• Dog
• Incomplete
– Expresses only some
features
• Dog as an animal
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
33
Terms according to
Comprehension
• Generic
– Common feature
• Being
• Paracetamol
• Specific
– Distinctive feature
• Rational
• Biogesic
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
34
Terms according to Extension
• Common
– General term
• Professor
• Individual
– One object
• Proper Name
– Prof. Dumbledore
• Particular Circumstance
– Head Professor of
Hogwarts
• Demonstrative Pronoun
– This Professor
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
35
Terms according to Extension
• Distributive
– Essence of entities
singularly
• Fish
• Ant
• Collective
– Essence of entities as
group
• School of Fishes
• Colony of Ants
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
36
Terms according to Extension
• Universal
– represents not only a class as a whole
but also each member of the class
• table, chair, stone
• Collective
– represents a number of things
constituting a unit-group or whole
• family, choir, band, team
• Particular
– represents only a part of the
universal whether it is definite or
indefinite
• three kings, few guests
• Singular
– represents a single object
• My father, this book
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
37
Activity
• Topic
– Terms according to
Extension
• Instruction
– Identify the term
according to extension:
• Universal
• Collective
• Particular
• Singular
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
38
Inverse Relationship between
Comprehension and Extension
COMPREHENSION (S-U)
SUPPOSITION
EXTENSION (U-S)
INTENSION
SUBSTANCE Substance Angel, Mineral, Plant,
Brute, Man
BODY Corporeal Substance Mineral, Plant, Brute,
Man
ORGANISM Animate Corporeal
Substance
Plant, Brute, Man
ANIMAL Sentient Animate
Corporeal Substance
Brute, Man
MAN Rational Sentient
Animate Corporeal
Substance
Man
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
39
Inverse Relationship between
Comprehension and Extension
• Comprehension
– Supposition
– Stands for a definite one
of the various things it
can stand
• Chair
– Five letter word
– Furniture
– Chairman
• Extension
– Intension
– Ascribed meaning
• Giving example
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
40
Activity
• Topic
– Inverse Relationship
between
Comprehension and
Extension
• Each number contains a
pair of terms.
• Identify whether the
terms are ordered
according to
Comprehension or
Extension.
• Arrange the following
according to the order of
Extension
• Comprehension
• Extension
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
41
Terms according to Meaning
• Univocal
– Same meaning
• Human as Person and
Human as Person
• Analogous
– Related meaning
– Depends on application
• Falling as motion and Falling as
in love
• Equivocal
– Different meaning
• Mouse of computer and Mouse
in the hole of the house
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
42
Activity
• Topic
– Terms according to
meaning
• Instruction
– 1. Classify the italicized
term in the following
sentences according to
meaning.
• Univocal
• Analogous
• Equivocal
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
43
Terms according to Perfection
• Precise
– Exact manner
• Triangle
– Right Triangle
• Imprecise
– Not exact manner
• Acute Triangle
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
44
Terms according to Perfection
• Clear
– Distinct manner
• Man as rational being
• Obscure
– Vague
– Indistinct manner
• Man as talking animal
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
45
Terms according to Perfection
• Adequate
– Man as rational being
• Inadequate
– Man as being
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
46
Terms according to Origin/ Formation
• Immediate/ Intuitive
– Direct observation of
things
• Water is liquid
• Ice is solid
• Mediate/ Abstracted
– Matters of Faith
• Man derives from ape
• God is the beginning of all
things
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
47
Terms according to Origin/ Formation
• Explicit
– Directly expressed
• “I love you.”
• Implicit
– Directly implied
– Matter of presumption
• Kiss, Hug
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
48
Terms according to Origin/ Formation
• Ideal/ Mental
– Mind envisions
• Heaven on earth
• Classless society
• Subjective/ Arbitrary
– Personal thinking
– Judgment of man
• Man came from Adam
• Real/ Objective
– Factual reality
• Woman Lawyer
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
49
Terms according to Relation
• Identical
– Same idea
• Human Person and
Rational being
• Equivalent
– Not the same formal
features
• Salt and Sodium Chloride
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
50
Terms according to Relation
• Pertinent
– Related to each other
• Rationality and Learning
• Freedom and Responsibility
• Authority and Responsibility
• Right and Obligation
• Impertinent
– Not related to each other
• Intellect and Gender
• Age and Maturity
• Wisdom and Race
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
51
Terms according to Relation
• Similar
– Same extension but different
comprehension
• Coffee and Barako
• Writer and Journalist
• Compatible
– Coexist in a subject
• Beauty and Brain
• Tall, Dark and Handsome
• Reason and Faith
• Incompatible
– That cannot coexist
• Sin and Holiness
• Health and Sickness
• Wisdom and Foolishness
• Division of Incompatible
Terms
– Contradictory
• Extremely opposite
– Living and Dead
– Hot and Cold
– High and Low
– Contrary
• Opposed in certain order
– Rich and Poor
– Tall and Short
– Privative
• Concept and its defect
– Sight and blindness
– Hearing and deafness
– Correlative
• Mutual relation
– Master and Servant
– Husband and Wife
– Student and Teacher
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
52
Terms according to Object
• Real/ Concrete
– Expresses something that has
existential actuality
• Chair, Table
• Abstract/ Logical
– Conceptual device to
facilitate learning
• Democracy
• Arbitrary/ Imaginary
– No correspondent reality
• Spiderman, Flying Carpet
• Metaphorical
– Stand for an allied meaning
• Lamb of God
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
53
Activity
• Topic
– Terms according to
Comprehension, Relation and
Object
• Instruction
– Identify the term according to
comprehension, relation and
object:
• Compatible or Incompatible
• Absolute/ Privative or
Relative
• Arbitrary or Real
• Concrete or Abstract
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
54
Terms according to Quality
• Positive Form, Positive
Meaning (+) (+)
– Life, Truth, Freedom
• Positive Form, Negative
Meaning (+) (-)
– Happy-go-lucky
• Negative Form, Negative
Meaning (-) (-)
– Illegal, Impolite
• Negative Form, Positive
Meaning (-) (+)
– Immortal, Infinite
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
55
Activity
• Topic
– Terms according to
Quality
• Instruction
– Classify the following
terms according to
Quality
• (+) (+)
– Positive Form, Positive
Meaning
• (+) (-)
– Positive Form, Negative
Meaning
• (-) (-)
– Negative Form, Negative
Meaning
• (-) (+)
– Negative Form, Positive
Meaning
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
56
Predicaments
• Substance
• Man, Dog, Plant
• Accident
– Quantity
• 50 kg.; 100 pesos; 25 ft. long
– Quality
• intelligent, red, hot, strong, healthy, beautiful
– Relation
• father, husband
– Action/ Activity
• running, walking, dancing, driving
– Passion
• being killed, was shot, are burned, to be lifted
– Time
• now, today, at 8 pm, next week, noon,
morning
– Place
• here, in the office, Davao, Manila, in the air
– Posture/ Position
• lying, standing, sitting
– Habit/ Possession
• in red gown, covered with lace , dressed, armed
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
57
Activity
• Topic
– Predicaments
• Instructions
• Identify the italicized
terms according to its
category/
predicaments.
• Substance
• Quantity
• Quality
• Relation
• Action
• Passion
• Time
• Place
• Posture
• Habit
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
58
Predicables
• Genus
– Specie in a class
• E.g. Triangle is a polygon
• Specific Difference
– Differences of the specie from
others
• E.g. Triangle is three-sided
• Species
– complete essence of a thing
• E.g. Triangle is a three-sided polygon
• Accident
– Something that attributes the thing
by contingency
• E.g. Acute Triangle
• Property
– Attribute
• E.g. Triangle has 25 Degrees on each side
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
59
Judgment
• Judgment
– Mental operation that
pronounces the
agreement or
disagreement between
two ideas
– E.g.
• Square and Polygon
– Square is a Polygon
• Table and Chair
– Table is not a Chair
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
60
Proposition
• Subject statement
– True or False
• Logic is the study of the
principles of correct
reasoning.
• Being a president is like
riding a tiger.
• Charles Dickens wrote
Romeo and Juliet.
02/10/17 03:00 AM 61
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Proposition
• Subject statement
– Affirmed or Denied
• God exists.
• Atlantis uncovered.
02/10/17 03:00 AM 62
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Proposition
• Subject statement
– affirm or deny the
attribute of a subject.
• A dog is an animal.
• A dog is not a cat.
02/10/17 03:00 AM 63
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Proposition
• Subject statement
– affirm or deny the
relationships,
connections between
member propositions.
• If it is raining, the
ground is probably wet.
02/10/17 03:00 AM 64
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Activity
• Topic
– Proposition
• Instruction
– 1. Identify which of the
following is a Proposition
and which is not.
– 2. Write P if the
statement is proposition
and N if it is not.
– 3. Write the answer on
the blank provided in
each sentence.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
65
Activity
• Topic
– Proposition
• Instruction
– Establish whether this
proposition is true or
false.
– Explain
• True
• False
• True and False
• I refuse to answer True
or False
02/10/17 03:00 AM 66
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Types of Proposition
• Causal
• Modal
• Inferential
• Simple
• Compound
• Existential
• Non-existential
• Categorical
• Hypothetical
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
67
Elements of Proposition
• Subject
– Something that is being
talked about in the
Proposition
– Something that is denied or
affirmed
• Copula
– Linking verb
– Tense
• Predicate
– Something that talks about
the Subject
– Affirmed or denied by the
Subject
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
68
Structure of Proposition
• Quantifier (Form)
– All
• Subject (Matter)
– students majoring in
philosophy
• Copula (Form)
– are
• Predicate (Matter)
– required to take
Metaphysicsand
Epistemology
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
69
Quantifiers
• Universal Quantifier
– All ( Affirmative )
– Every ( Affirmative )
– Any ( Affirmative )
– No ( Negative )
– None ( Negative )
• Particular Quantifier
– Some
– At least one
– Most
– Almost all
– The majority
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
70
Categorical Proposition
• A (Universal-Affirmative)
• All S are P
– All politicians are honorable
men.
• I (Particular-Affirmative)
• Some S are P
– Some politicians are
honorable men.
• E (Universal-Negative)
• All S are not P
– All politicians are not
honorable men.
• O (Particular-Negative)
• Some S are not P
– Some politicians are not
honorable men.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
71
Affirmative Negative
Universal A E
Particular I O
Double Negation
• Negative + Negative =
Positive
• Offset Rule
• Bullet and Train
Method
• E.g.
– No man is not mortal by
nature.
– He who did not vote for
Roxas last national
election was not
convinced of his
leadership.
• E.g.
– No dogs that are without
pedigrees are candidates
for the blue ribbon in
official dog shows.
– Not all ordained
ministers are not holy.
– Nothing that is material
is indestructible.
– Most sins are not
unforgivable.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
72
Modal Propositions
• (A) Necessary Mode
– An absolute being must exist.
– It is necessary for cats to purr.
• (E) Impossible Mode
– Angels cannot be mortals.
– It is impossible for squares to be
circulars.
• (I) Possible Mode
– This car can run 300 mph.
– It is possible for believer to become
saints.
• (O) Unnecessary Mode
– It is not necessary for God to be
creator just to become God.
– It is contingent for tables to have
four legs.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
73
Quality of Proposition
• Not all
– Particular Negative
• Last but not the least
– Affirmative
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
74
Hypothetical Proposition
• Disjunctive Proposition
– Either-or (+) (-)
• The will is either free or
determined.
• Conjunctive Proposition
– All cannot be true (-) (-)
• You cannot work and play at the
same time.
• Conditional Proposition
– If-then (+) (+)
• If a man works, then he deserves
the reward of his labor.
• Biconditional Proposition
– If and only if (+) (+)
• You will pass this course if and only if
you will study hard.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
75
Activity
• Topic
– Hypothetical Proposition
• Instruction
– 1. State the correct
hypothetical
proposition.
• Conditional
• Biconditional
• Conjunctive
• Disjunctive
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
76
Activity
• Topic
– Categorical Proposition I
• Instruction
– 1. Classify the following
Proposition according to
quantity, quality and
symbol.
• Quantity
– Universal
– Particular
• Quality
– Affirmative
– Negative
• Symbol
– A
– I
– E
– O
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
77
Activity
• Topic
– Categorical Proposition II
• Instruction
– 1. Give the correct
symbol of the following
categorical proposition.
• A
• I
• E
• O
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
78
Inference
• Inference
– The conclusion is
reached
– Meanings are already
implied in the former
• Non-inference
– The conclusion is not
reached
• From the given premise:
– The birds are flying south.
– She graduated summa cum
laude.
– Lights are out and their car is
gone.
– The cat is standing by her dish
meowing.
• Infer the conclusion:
– I suspect they are not home.
– She is probably hungry.
– Winter must be coming.
– She must have studied hard in
college.
02/10/17 03:00 AM 79
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Types of Inference
• Immediate
– Draws conclusion from
any proposition
• Opposition
• Logical Proposition
• Eduction
– Interchanging the
subject and predicate
– Putting or removal of
negatives
• Mediate
– Draws conclusion from
series of proposition
• Categorical Syllogism
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
80
Square of Opposites
Every S is P No S is P
Some S is P Some S is not P
02/10/17 03:00 AM 81
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
• Contrariety
– Contraries
• Contradiction
– Contradictories
• Subalternation
– Subalterns
• Subcontrariety
– Subcontraries
Laws of Contradiction
• Rule:
– If A is true, O is false.
– If E is true, I is false.
– If A is false, O is true.
– If E is false, I is true.
– If O is true, A is false.
– If I is true, E is false.
– If O is false, A is true.
– If I is false, E is true.
– A - All dogs are animals.
– O - Some dogs are not
animals.
– E - No women are married.
– I - Some women are
married.
– O - Some prisoners are not
guilty.
– A - All prisoners are guilty.
– I - Some apples are oranges
– E - No apples are oranges.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
82
Laws of Contrariety
• Rule:
– If A is true, E is false.
– If A is false, E is doubtful.
– If E is true, A is false.
– If E is false, A is doubtful.
– A - All cats are animals. True
– E - No cats are animals. False
– E - No cats are dogs. True
– A - All cats are dogs. False
– A - All flowers are roses. False
– E - No flowers are roses. False
– E - No Catholic priests are
ordained. False
– A - All Catholic priests are
ordained. True
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
83
Laws of Subcontrariety
• Rule:
– If I is false, O is true.
– If I is true, O is doubtful.
– If O is false, I is true.
– If O is true, I is doubtful.
– I - Some triangles are squares.
False
– O - Some triangles are not squares.
True
– O- Some students are not present.
False
– I - Some students are present.
True
– I - Some basketball players are tall.
True
– O - Some basketball players are not tall.
True
– O - Some scholars are not dumb.
True
– I - Some scholars are dumb.
False
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
84
Laws of Subalternation
• Rule 1:
– If A is true, I is true.
– If E is true, O is true.
– If A is false, I is doubtful.
– If E is false, O is doubtful.
– A - All surgeons are doctors.
True
– I - Some surgeons are doctors.
True
– E - No beauty titlist is ugly.
True
– O - Some beauty titlists are not ugly.
True
– A - All students are scholars.
False
– I - Some students are scholars.
True
– E - No dogs are animals.
False
– O- Some dogs are not animals.
False
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
85
Laws of Subalternation
• Rule 2:
– If I is false, A is false.
– If O is false, E is false.
– If I is true, A is doubtful.
– If O is true, E is doubtful.
– I - Some devils are good.
False
– A - All devils are good.
False
– O - Some angels are not spiritual.
False
– E - No angels are spiritual.
False
– I - Some oranges are fruits.
True
– A - All oranges are fruits.
True
– O - Some athletes are not swimmers.
True
– E - No athletes are swimmers.
False
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
86
Chart – Opposition of Proposition
A E I O
A True T F T F
E True F T F T
I True D F T D
O True F D D T
A False F D D T
E False D F T D
I False F T F T
O False T F T F
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
87
Activity
• Topic
– Square of Opposition
• Instruction
– Determine whether the following
inferences are correct or
incorrect
– From the truth or falsity of the
given statement, determine the
symbol, judgment and
relationship of the following
statements
– Indicate “The same proposition”
if the relationship came from the
same symbol and the same
judgment
– Encircle the symbol and
judgment and write the
relationship
• Precision
– Correct
– Incorrect
• Symbol
– A
– I
– E
– O
• Judgment
– True
– False
– Doubtful
• Relationship
– Contradiction
– Contrariety
– Subcontrariety
– Subalternation
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
88
Eduction
• Conversion
– Switch S and P
Symbol Statement Converse Truth Value
E No S are P No P are S Same
I Some S are P Some P are S
A All S are P All P are S Undetermined
O Some S are not
P
Some P are
not S
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
89
Eduction
• Obversion
– Change the Quality
– Negate P
Symbol Statement Obverse Truth Value
A All S are P No S are non P Same
E No S are P All S are non P
I Some S are P Some S are
non P
O Some S are not
P
Some S are not
non P
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
90
Eduction
• Contraposition
– Switch and Negate S and P
Symbol Statement Contrapositive Truth Value
A All S are P All non P are
non S
Same
O Some S are not
P
Some non P
are not non S
E No S are P No non P are
non S
Undetermined
I Some S are P Some non P
are non S
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
91
Eduction
• Inversion 1
– Change the Quantity from Universal to Particular
– Particular Quantity cannot be inversed
– Change the Quality of Subject and Predicate
Symbol Statement Inverse Truth Value
A Every S is P Some non S is non
P
Same
E Every S is not P Some non S is P
I Cannot be inversed
O
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
92
Eduction
• Inversion 2
– Change the Quantity from Universal to Particular
– Particular Quantity cannot be inversed
– Change the Quality of Subject and Predicate
Symbol Statement Inverse Truth Value
A Every S is P Some non S is non
P
Same
E Every S is not P Some non S is not
non P
I Cannot be inversed
O
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
93
Activity
• Topic
– Eduction I
• Instruction
– 1. Identify the correct
Eduction of the following
proposition
– 2. Write the letter of
your choice on the space
provided
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
94
Activity
• Topic
– Eduction II
• Instruction
– State the correct
Eduction of the following
proposition
– Double Negation does
not apply
– Simplifying “Not all” to
“Some” does not apply
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
95
Argument
• Group of Proposition in
which the Premises
result in Conclusion.
• Premise 1
– Anything that moves is
moved by another;
• Premise 2
– But, the ball moves;
• Conclusion
– Ergo, the ball is moved
by another.
02/10/17 03:00 AM 96
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Structure of Argument
• Premise 1
– Anything that moves is
moved by another;
• Given Proposition
• Premise 2
– But, the ball moves;
• reason of the conclusion
• serves as the evidence
• Conclusion
– Ergo, the ball is moved by
another.
• Offshoot
• Claim being made
• followed the evidence
02/10/17 03:00 AM 97
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Not arguments
• Raisins are dried grapes.
Prunes are dried plums.
• These are some of the
symptoms of neurosis:
strong guilt feeling,
irrational fears, insomnia,
and inability to make
decisions.
• It is sunny today. It is also
the beginning of the week.
02/10/17 03:00 AM 98
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Good Argument
• Conclusion is a result of
Premise
• Premise
– It had rained yesterday,
• Conclusion
– Some places have been
flooded.
02/10/17 03:00 AM 99
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Bad Argument
• Conclusion is not a
result of Premise
• Premise
– Identical twins who
inherit the same genes
have different
intelligence quotient.
• Conclusion
– Environment must have
played a role in
determining intelligence.
02/10/17 03:00 AM 100
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Premise Indicators
• since
• because
• for
• as
• follows from
• as shown by
• In as much as
• as indicated by
• the reason is that
• may be inferred from
• may be derived from
• may be deduced from
• in view of the fact that
• in that
• seeing that
• given that
• may be concluded from
• on the reason that
• due to the fact that
• based on the premise that
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
101
Conclusion Indicators
• therefore
• hence
• thus
• so
• wherefore,
• accordingly,
• in consequence
• consequently
• proves that
• as a result
• for this reason
• it follows that
• we may infer
• I conclude that
• which shows that
• which means that
• which entails that
• which implies that
• which allows us to infer
• which points to the
conclusion that
• it must be that
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
102
Activity
• Topic
– Premise and Conclusion
• Instruction
– 1. Identify the premise and
the conclusion in the
following propositions
– 2. Indicate the indicator of
the respective premise and/
or conclusion
– 3. Underline the Premise and
Conclusion
– 4. Write P above the Premise
and C above the Conclusion
– 5. Encircle the Indicator
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
103
Premise precedes Conclusion e. g.
• Premise
– The investigation of
supernatural
phenomena lies outside
the realm of science.
• Conclusion
– Ergo, science can neither
prove nor disprove the
existence of God.
02/10/17 03:00 AM 104
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Premise precedes Conclusion e. g.
• Premise
– Because many are
rightly concerned about
the troublesome state of
affairs that currently
exists between Christian
and Moslem in Egypt.
• Conclusion
– It is understandable to
look to the legal system
for help in addressing
the problem.
02/10/17 03:00 AM 105
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Premise precedes Conclusion e. g.
• Premise
– Wisdom is the principal
thing;
• Conclusion
– Ergo, seek the pursuit of
wisdom.
02/10/17 03:00 AM 106
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Premise precedes Conclusion
• shows that
• indicates that
• proves that
• entails that
• implies that
• establishes that
• Activity
– Make propositions using
these indicators.
02/10/17 03:00 AM 107
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Conclusion precedes Premise e. g.
• Conclusion
– The Food and Drug
Administration should
stop all cigarette sales
immediately.
• Premise
– After all, cigarette
smoking is the leading
preventable cause of
death.
02/10/17 03:00 AM 108
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Conclusion precedes Premise e. g.
• Conclusion
– Moreover, cutting SSS
will not improve the
deficit problem. As the
Secretary of Department
of Budget has noted,
• Premise
– Social security is funded
by separate payroll taxes
and contributes not a
peso to the deficit.
02/10/17 03:00 AM 109
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Conclusion precedes Premise
• Activity
– Make propositions using
these indicators.
• is shown by
• is indicated by
• is proven by
• is entailed by
• is implied by
• is established by
02/10/17 03:00 AM 110
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Activity
• Topic
– Premise precedes
Conclusion and
Conclusion precedes
premise
• Instruction
– 1. Write N if it is not an
argument.
– 2. If it is an argument,
write PC if the Premise
precedes Conclusion.
– 3. Write CP if the
Conclusion precedes
Premise
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
111
Statement to Argument
• The president, being
human, is mortal, as all
human beings are
mortal.
• Premise 1
– All human beings are
mortals.
• Premise 2
– The president is a human
being.
• Conclusion
– Ergo, the president is
mortal.
02/10/17 03:00 AM 112
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Statement to Argument
• God does not exist
because if he did there
would be no suffering
and evil in the world;
but obviously suffering
and evil do exist. Thus,
there is no God.
• Premise 1
– If God existed there
would be no suffering
and evil in the world.
• Premise 2
– But obviously suffering
and evil do exist.
• Conclusion
– Ergo, there is no God.
02/10/17 03:00 AM 113
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Statement to Argument
• All mammals feed their
young with milk. All
humans are mammals.
Ergo, all humans feed
their young with milk.
• Activity
– Transform the
statement into an
argument.
02/10/17 03:00 AM 114
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Statement to Argument
• All that feed their young
with milk are mammals.
All humans feed their
young with milk. Ergo,
all humans are
mammals.
• Activity
– Transform the
statement into an
argument.
02/10/17 03:00 AM 115
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Reasoning
• Reasoning
– Mental operation in
which propositions are
compared into order to
create a meaningful
conclusion.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
116
Validity of Reasoning
• Rules:
– The conclusion should
flow from the material
content of the premise
– An argument containing
true premises cannot
have a false conclusion
• Valid E.g.
– All sharks are ferocious
animals.
– However, some sea creatures
are sharks.
– Ergo, some sea creatures are
ferocious animals.
• Invalid E.g.
– All stars are heavenly bodies.
– However, Angelina Jolie is a
star.
– Ergo, Angelina Jolie is a
heavenly body.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
117
Activity
• Topic
– Validity of Reasoning
• Instruction
– Identify whether the
argument is Valid or
Invalid
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
118
Types of Reasoning
• Deduction
– From General to Specific
– Determines whether the
argument is Valid of
Invalid
– Core of Aristotelian Logic
– E.g.
• All businessmen are
millionaires
• However, some
businessmen are Filipinos
• Ergo, some Filipinos are
millionaires.
• Induction
– From Specific to General
– Philosophy of Francis
Bacon and John Stuart
Mill
– Determines whether the
argument is correct or
incorrect.
– E.g.
• Juan is a Filipino
• Juan is a hardworking man.
• Ergo, probably all
hardworking men are
Filipinos.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
119
Kinds of Reasoning
• Deductive
– Conclusion follows
necessarily from
premise.
– Premise supports
conclusion because it is
true.
– Because it is impossible
for the conclusion to be
false.
• Inductive
– Conclusion follows
probably from premise.
– Premise supports
conclusion because of it
is assumedly true.
– Because it is probable
for the conclusion to be
true.
02/10/17 03:00 AM 120
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
Deductive
• Indicators
– Necessarily
– Certainly
– Absolutely
– Definitely
• E.g.
– If a substance is a noble
gas, it is inert.
Therefore, since argon is
a noble gas, it
necessarily follows that
it is inert.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
121
Inductive
• Indicators
– Probable
– Improbable
– Plausible
– Implausible
– Likely
– Unlikely
• E.g.
– Neon has unstable
isotopes. Therefore,
since argon is similar in
many ways to neon, it
probably follows that
argon has unstable
isotopes, too.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
122
Deductive vs. Inductive
• Deductive
– Premise 1
• All saleswomen are
extroverts.
– Premise 2
• Judy Wage is a
saleswoman.
– Conclusion
• Therefore, she is
extrovert.
• Inductive
– Premise 1
• The vast majority of
saleswomen are
extroverts.
– Premise 2
• Rose Liam is a
saleswoman.
– Conclusion
• Therefore, she is
extrovert.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
123
Deductive and Inductive
• Arguments with no
indicator
– Depends on the Matter
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
124
Forms of Deductive Reasoning
• Argument based on
mathematics
– An argument in which
the conclusion depends
on some purely
arithmetic or geometric
computation or
measurement.
• E.g.
– A shopper may place two
apples and three oranges into
a paper bag and then
conclude that the bag
contains five fruits.
– A surveyor might measure a
square piece of land and,
after determining that it is
100 feet on each side,
conclude that it contains
10,000 square feet.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
125
Forms of Deductive Reasoning
• Argument from
definition
– An argument in which
the conclusion is claimed
to depend upon the
definition of some word
or phrase used in the
premise or the
conclusion
• E.g.
– Claudia is mendacious,
so she tells lies.
– This paragraph is prolix,
so it follows that it is
excessively wordy.
• Dictionary:
– Mendacious
• Liar
– Prolix
• Prolonged
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
126
Forms of Deductive Reasoning
• Categorical syllogism
– A syllogism in which
each statement begins
with one of these
quantifiers:
• All
• No
• E.g.
– Premise 1
• All lasers are optical
devices.
– Premise 2
• Some lasers are surgical
instruments.
– Conclusion
• Therefore, some optical
devices are surgical
instruments.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
127
Forms of Deductive Reasoning
• Conditional syllogism
– A syllogism having a
conditional statement
for one or both of its
premises.
• E.g.
– Premise 1
• If quartz scratches glass,
then quartz is harder than
glass.
– Premise 2
• Quartz scratches glass.
– Conclusion
• Therefore, quartz is
harder than glass.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
128
Forms of Deductive Reasoning
• Disjunctive syllogism
– A syllogism having a
disjunctive statement
(“either...or”) for one or
both of its premises.
• E.g.
– Premise 1
• Either breach of contract
is a crime or it is not
punishable by the state.
– Premise 2
• Breach of contract is not
a crime.
– Conclusion
• Therefore, it is not
punishable by the state.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
129
Forms of Inductive Reasoning
• Prediction
– The premises deal with
some known event in
the present or past, and
the conclusion moves
beyond this event to
some event in the
relative future.
• E.g.
– Because certain
meteorological
phenomena have
been observed to
develop over a certain
region in the Pacific, a
storm will occur there in
the next several hours.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
130
Forms of Inductive Reasoning
• Argument from analogy
– An argument that
depends on the analogy
between two things.
• E.g.
– From knowledge that his
Mercedes car is an
expensive car, I argue
that your car, being a
Mercedes, is also
expensive.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
131
Forms of Inductive Reasoning
• Inductive generalization
– An argument that
proceeds from the
knowledge of a selected
sample to some claim
about the whole group.
Because the members of
the sample have a
certain characteristic, it
is argued that all the
members of the group
have the same
characteristic.
• E.g.
– One may argue that
because three oranges
selected from a certain
crate were especially
tasty and juicy, all the
oranges from that crate
are especially tasty and
juicy.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
132
Forms of Inductive Reasoning
• Argument from
authority
– An argument in which
the conclusion rests
upon a statement made
by some presumed
authority or witness.
• E.g.
– A lawyer may argue that
the suspect committed
no murder because an
eyewitness testified to
that effect under oath.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
133
Forms of Inductive Reasoning
• Argument based on
signs
– An argument that
proceeds from the
knowledge of a certain
sign.
• E.g.
– When driving on an
unfamiliar highway, one
might see a sign
indicating that the road
makes several sharp
turns one mile ahead.
Based on this
information, one might
argue that the road does
indeed make several
sharp turns one mile
ahead.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
134
Forms of Inductive Reasoning
• Causal inference
– An argument that
proceeds from the
knowledge of a cause to
knowledge of the effect
– An argument that
proceeds from the
knowledge of an effect
to knowledge of a cause.
• E.g. Cause to effect
– From the knowledge
that a bottle of wine had
been accidentally left in
the freezer overnight,
someone might conclude
that it had frozen.
• E.g. Effect to Cause
– after tasting a piece of
chicken and finding it dry
and crunchy, one might
conclude that it had
been overcooked.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
135
Activity
• Topic
– Kinds of Reasoning
• Instruction
– 1. Identify whether the
argument is Deductive
or Inductive
– 2. Indicate the form of
the respective argument
– 3. Write the answer on
the blank provided in
each sentence.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
136
Syllogism
• Syllogism
– Deductive Argument
– Composed of three proposition
• Major Premise
– Consist of Predicate Term of the
Conclusion and a Middle Term
– Usually begin with Universal
quantifier
• Minor Premise
– Consist of Subject Term of the
Conclusion and a middle term
• Conclusion
– Composed of:
» Predicate of the Major
premise
» Subject of the Minor
Premise
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
137
Perfect Syllogism
• Categorical
– Simple
– Compound
• Hypothetical
– Conditional
– Conjunctive
– Disjunctive
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
138
Components of Syllogism
• Major Premise
– All men are mortal.
(M) (T)
• Minor Premise
– All Filipinos are men.
(t) (M)
• Conclusion
– Ergo, all Filipinos are
(t)
mortal.
(T)
• Major Term (T)
– Predicate of the Conclusion
– Occurrence: Conclusion and One
of the Premise
• Minor Term (t)
– Subject of the Conclusion
– Occurrence: Conclusion and in the
Premise where the Major Term
does not occur
• Middle Term (M)
– Unites the Major and Minor Term
– Does not occur in the Conclusion
– Occurrence: Major and Minor
Premise
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
139
Steps in Categorical Syllogism
• Major Premise
– All men are mortal.
(M) (T)
• Minor Premise
– All Filipinos are men.
(t) (M)
• Conclusion
– Ergo, all Filipinos are
(t)
mortal.
(T)
• 1. Look for Conclusion
• 2. Predicate in Conclusion
– Major Term (T)
• 3. Subject in Conclusion
– Minor Term (t)
• 4. Premise with the Major Term
(T)
– Major Premise
• 5. Premise with the Minor Term (t)
– Minor Premise
• 6. Common Term in the Major
Premise and Minor Premise
– Middle Term (M)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
140
Activity
• Topic
– Categorical Syllogism Steps
• Instruction
– 1. Identify the Major Premise,
Minor Premise and
Conclusion.
– 2. Underline and identify the
Major Term (T), Minor Term
(t) and Middle Term (M) using
the proper symbols following
the Steps in Categorical
Syllogism.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
141
Rules of Categorical Syllogism
• Rule No. 1
– There must be only three
categorical proposition
• All golds are metals.
• All jewelries are golds.
• Ergo, all jewelries are
metals.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
142
Rules of Categorical Syllogism
• Rule No. 2
– There must be only three
univocal terms, each of
which occurs twice but
not in the same
proposition
• All flowers are beautiful.
(M) (T)
• Tulip is a flower.
(t) (M)
• Tulip is beautiful.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
143
Rules of Categorical Syllogism
• Rule No. 3
– The middle term must be
distributed (Universal) at
least once
• All trees are plants.
(M) (T)
• All Bonsai are trees.
(t) (M)
• Ergo, all Bonsai are plants.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
144
Rules of Categorical Syllogism
• Rule No. 4
– If the term is distributed
(Universal) in the
conclusion, then such
term must be distributed
(Universal) in a premise
• Major and Minor terms
must not be universal in
the conclusion if they are
not universal in the
premises.
• Some metals are cars.
(M) (T)
• All robots are metals.
(t) (M)
• Ergo, all robots are cars.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
145
Rules of Categorical Syllogism
• Rule No. 5
– There must be no two
particular premises; one
premise must be
universal
• Some metals are gold.
(M) (T)
• All rings are metals.
(t) (M)
• Ergo, all rings are gold.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
146
Rules of Categorical Syllogism
• Rule No. 6
– If one premise is
particular, the
conclusion must be
particular
• Some stones are pearl.
(M) (T)
• All crowns are stones.
(t) (M)
• Ergo, some crowns are
pearl.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
147
Rules of Categorical Syllogism
• Rule No. 7
– If the conclusion is
negative, only one
premise must be
negative
• All stars are cute.
(T) (M)
• Some comedians are not cute.
(t) (M)
• Ergo, some comedians are not
stars. (t)
(T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
148
Rules of Categorical Syllogism
• Rule No. 8
– If the conclusion is
affirmative then both
premises must be
affirmative
• All legislators are senators.
(t) (M)
• All senators are honest.
(M) (T)
• Ergo, all legislators are honest.
(t) (T)
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
149
Activity
• Topic
– Categorical Syllogism
Rules
• Instruction
– 1. Identify the Rule
Violated in the following
Categorical Syllogism
– 2. Write the rule
statement beside the
given Syllogism.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
150
Figures of Categorical Syllogism
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
151
Figure 1 Figure 2
M P
S M
S P
P M
S M
S P
Figure 3 Figure 4
M P
M S
S P
P M
M S
S P
Moods of Categorical Syllogism
• Valid Moods of Figure 1
– AAA Barbara
– AII Darii
– EAE Celarent
– EIO Ferio
• Valid Moods of Figure 2
– AOO Baroco
– AEE Camestres
– EAE Cesare
– EIO Festino
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
152
Moods of Categorical Syllogism
• Valid Moods of Figure 3
– AAI Darapti
– AII Datisi
– EAO Felapton
– EIO Ferison
– IAI Disamis
– OAO Bocardo
• Valid Moods of Figure 4
– AAI Bramantip
– AEE Camenes
– EAO Fesapo
– EIO Fresison
– IAI Dimaris
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
153
Activity
• Topic
– Categorical Syllogism -
Figures and Moods
• Instruction
– 1. Determine the Figures
and Moods of the
following Categorical
Syllogism
– 2. Write your answer of
the space provided
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
154
Hypothetical Syllogism
• Hypothetical Syllogism
– Contains major premise
that is hypothetical
proposition
– Forms:
• Conditional Syllogism
• Conjunctive Syllogism
• Disjunctive Syllogism
• E.g.
– If penguins are birds then
they have feathers and
wings.
– However, penguins are
birds.
– Ergo, they have feathers
and wings.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
155
Conditional Syllogism
• Conditional Syllogism
– Have conditional major
premise
– Indicators:
• If then
– Modus Ponens
• Posit the antecedent and
the consequent
– Structure
• S P
• S
• P
• E.g. Valid
– If you are beautiful then you
have many admirers.
– However, you are beautiful
– Ergo, you have many
admirers.
• E.g. Invalid
– If you are beautiful then you
have many admirers.
– However, you have many
admirers.
– Ergo, you are beautiful.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
156
Conditional Syllogism
• Conditional Syllogism
– Have conditional major
premise
– Indicators:
• If then
– Modus Tollens
• Sublate the consequent
and antecedent
– Structure
• S P
• P
• S
• E.g. Valid
– If you are an athlete then you
are energetic.
– However, you are not
energetic.
– Ergo, you are not an athlete.
• E.g. Invalid
– If you are an athlete then you
are energetic.
– However, you are not an
athlete.
– Ergo, you are not energetic.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
157
Activity
• Topic
– Conditional Syllogism
• Instruction
– Identify whether the
argument is a valid
Modus Ponens or Modus
Tollens
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
158
Conjunctive Syllogism
• Conjunctive Syllogism
– Indicator:
• And
– Ponendo-Tollens
• Posit one term of the
major premise in the
minor premise
• Sublate one term of the
major premise in the
conclusion
– Structure
• Positive Minor Premise
• Negative Conclusion
• E.g. Valid
– You cannot be a manager and
a janitor at the same time
– However, you are a manager.
– Ergo, you are not a janitor.
• E.g. Invalid
– You cannot be a manager and
a janitor at the same time
– However, you are not a
manager.
– Ergo, you are a janitor.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
159
Activity
• Topic
– Conjunctive Syllogism
• Instruction
– Identify whether the
argument is Valid or
Invalid
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
160
Disjunctive Syllogism
• Disjunctive Syllogism
– Indicators:
• Either or
– Ponendo-Tollens
• Minor premise posits a
member of major premise
• Conclusion must Sublate
the other remaining
member
– Structure
• Major Premise cannot be
both true in Minor Premise
and Conclusion
• Positive Minor premise
• Negative Conclusion
• E.g. Valid
– Man is either biped or
quadruped.
– However, man is biped.
– Ergo, man is not quadruped.
• E.g. Invalid
– Man is either biped or
quadruped.
– However, man is biped.
– Ergo, man is quadruped.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
161
Activity
• Topic
– Disjunctive Syllogism
• Instruction
– Identify whether the
argument is Valid or
Invalid
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
162
Imperfect Syllogism
• Polysyllogism
– Enthymeme
• First Order
• Second Order
• Third Order
– Sorites
• Aristotelian
• Goclenian
– Dilemma
• Simple
• Complex
– Epichireme
• Explained with:
– Because
– Since
– Insofar
– In as much02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
163
Enthymeme
• First Order
– Major Premise is omitted
• Second Order
– Minor Premise is omitted
• Third Order
– Conclusion is omitted
• E.g.
– Given:
• Every artist is imaginative.
• However, Picasso is an artist.
• Ergo, he is imaginative.
– First Order
• Picasso is an artist.
• Ergo, he is imaginative.
– Second Order
• Every artist is imaginative.
• Ergo, Picasso is imaginative.
– Third Order
• Every artist is imaginative.
• Picasso is an artist.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
164
Activity
• Topic
– Enthymeme
• Instruction
– Fill the three orders of
Enthymeme
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
165
Sorites
• Aristotelian Sorites
– Predicate of the Premise is the
Subject of the Series of
Conclusion excluding Final
Conclusion
– Final Conclusion is composed of:
• Subject of the First Premise
• Predicate of the Last Conclusion
• Goclenian Sorites
– Reverse of Aristotelian Sorites
– Subject of the Premise is the
Predicate of the Series of
Conclusion excluding Final
Conclusion
– Final Conclusion is composed of:
• Subject of the Last Conclusion
• Predicate of the First Premise
• E.g. Aristotelian Sorites
– Philippines is an archipelago.
– An archipelago is a land surrounded by
water.
– A land surrounded by water is an
island.
– An island is a mass of land.
– A mass of land is not an ocean.
– Ergo, Philippines is not an ocean.
• E.g. Goclenian Sorites
– A mass of land is not an ocean.
– An island is a mass of land.
– A land surrounded by water is an
island.
– An archipelago is a land surrounded by
water.
– Philippines is an archipelago.
– Ergo, Philippines is not an ocean.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
166
Activity
• Topic
– Sorites
• Instruction
– Identify whether the
syllogism is Aristotelian
Sorites or Goclenian
Sorites
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
167
Fallacy Illicit Process
• Fallacy Illicit Process
– Violates the rules of
distribution
– Term appears to be
Universal or Particular in
the Conclusion, but not
in the Premise
– Positive Proposition
makes Particular
Predicate
– Negative Proposition
makes Universal
Predicate
• Fallacy Illicit Major
• Fallacy Illicit Minor
• Fallacy of Undistributed/
Particular Middle
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
168
Fallacy Illicit Major
• Fallacy Illicit Major
– Violates the rules of
distribution
– Major Term appears to be
Universal or Particular in the
Conclusion, but not in the
Major Premise
– Positive Proposition makes
Particular Predicate
– Negative Proposition makes
Universal Predicate
• E.g.
– All dogs are mammals.
• Middle Universal + Major
Particular
– No cats are dogs.
• Minor Universal - Middle
Universal
– Ergo, no cats are
mammals.
• Minor Universal - Major
Universal
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
169
Fallacy Illicit Minor
• Fallacy Illicit Minor
– Violates the rules of
distribution
– Minor Term appears to be
Universal or Particular in the
Conclusion, but not in the
Minor Premise
– Positive Proposition makes
Particular Predicate
– Negative Proposition makes
Universal Predicate
• E.g.
– All cats are felines.
• Middle Universal + Major
Particular
– All cats are mammals.
• Middle Universal + Minor
Particular
– Ergo, all mammals are
felines.
• Minor Universal + Major
Particular
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
170
Fallacy of Undistributed Middle
• Fallacy of Undistributed/
Particular Middle
– Violates the rules of
distribution
– Only one Middle Term must
be Particular
– Positive Proposition makes
Particular Predicate
– Negative Proposition makes
Universal Predicate
• E.g.
– All mammals are
animals.
• Major Universal + Middle
Particular
– Some animals are brute.
• Middle Particular + Minor
Particular
– Ergo, not all brute are
mammals.
• Minor Particular - Major
Universal
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
171
Debate
• Structure of Debate
– Constructive Speech
• Affirmative first
contender
– Interpellation
– Question
» Destroy
– Answer
» Defend
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
172
Debate• Types of Debate
– Lincoln-Douglas/ Two men
debate
• 1 Affirmative and 1 Negative
– Rebuttal
• 3 Members per side
• All members can rebut the
speaking opponent except the 1st
affirmative who will close the
debate
– Parliamentary/ Oregon-Oxford
• 3 Speakers
• 1st
speaker affirmative starts the
debate and be interprellated by the
1st
Speaker negative.
• 1st
speaker negative starts and be
interprellated by 2nd
speaker
affirmative and so on.
• 1st
speaker affirmative will
interprellate the last negative
speaker and will close the debate.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
173
Debate– Valid Objections
• Objection Your Honor/
Mr. Moderator, the
question is:
– Irrelevant/ Misleading/
Beyond the scope of
the topic
» Question is
nothing to do with
the topic
» Purposely
throwing off track
the topic
– Vague and Kilometric
» Question could not
be understood
– Immaterial/ Has no
basis/ Hearsay
» Doubtful evidence
– Hypothetical
» Based on assumptions
– Calling for Opinion
» Speculation
» Personal
» Beyond expertise
– Calling for two extremes
» Misleading choices
– Argumentative
» Cannot be proven
– Badgering
» Shouting
» No room for answer
– Leading
» Complex Question
– Repulsive to the Senses
» Pictures of dead, garbage, etc.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
174
Debate
– Qualifications
• Your Honor/ Mr.
Moderator
– May I qualify my
answer? The question is
complex.
– Questions
• Structured
– Series of deductions
• Single
– Seeking evidence that
opponent does not
have
• Straw
– Rapid Fire
» Rattles and
Pressure the other
side
• Rebuttal Speech
• Team Captain of both sides
– Fallacies
• Accidents
• False Cause
• Consequent
• Complex Question
• Begging the Question
• Absolute
• Ad Hominem
• Ad Populum
• Misericordiam
• Ad Verecundiam
• Ad Baculum
• Ad Ignorantiam
• Non-sequitor
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
175
Topics for Debate
• Should abortion be legal?
• Should death penalty be allowed?
• Should prostitution be legal?
• Should euthanasia be allowed?
• Should gay marriage be legal?
• Should divorce be legal?
• Should marijuana be legal?
• Should sex education be allowed?
• Is animal testing justified?
• Should polygamy be legal?
• Is social networking good for
society?
• Is age important factor in
relationship?
• Is male superior to female?
• Is money more important than
love in marriage?
• Should housewives be allowed to
be bread winner?
• Should homework be banned?
• Should Priest be allowed to
marry?
• Should Seminarians be allowed to
have girlfriends?
• Does God exist?
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
176
Fallacy
• Fallacy
– In English term
• Error
• Prejudice
• Mistaken Impression
• Illusion
• Fallacy
– In Logical term
• Fallere (Latin) to deceive
• Error of reasoning
• Inadequate evidence for
the conclusion.
• False argument that has
the appearance of truth
• Paralogism or ignorance
• Mistake in reasoning
– Mistake in judgment
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
177
Sophism
• Sophism
– Sophistry
– Fallacy committed with
the intention to deceive
or mislead an opponent
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
178
Formal Fallacies
• Fallacies of Ambiguity
– Fallacies of clearness
– Contain ambiguous
words or phrases
– Confusion in the
meaning of words
• Logical Fallacies
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
179
Dichotomy
• “Either . . . Or”
statement is used
• The alternatives are
falsely presented
exhaustively
• Eliminating the
undesirable alternative,
leaving the desirable
alternative
• E.g.
– Either you let me have a
grand debut party or I will be
miserable for the rest of my
life. I know you do not want
me to be miserable for the
rest of my life, so it follows
that you will have me a grand
debut party.
– Either you will cheat or fail in
the examination. Surely you
do not want to fail the
examination. Therefore, you
will cheat.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
180
Equivocation
• The same word or
phrase is used with two
or more meanings
• E.g.
– A law can be repealed by
legislative authority.
The law of gravity is a
law. Therefore, the law
of gravity can be
repealed by the
legislative authority.
– No designing persons
are to be trusted; But,
architects are people
who make designs;
Therefore, architects are
not to be trusted.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
181
Amphiboly
• The grammatical
construction of a
sentence is not clear
and is therefore open to
different interpretation
• E.g.
– John told Bob that he
had made a mistake. It
follows that John has at
least the courage to
admit his own mistakes
– My mother told your
mother that she should
go to the SSS office
– The dog of a lady with
long tail is lost
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
182
Composition
• What is true of the
parts of a whole is also
true of the whole thing
• Taking collectively what
should be taken
individually
• The whole is this
because the parts are
these
• E.g.
– A feather is light. Therefore, a
plastic containing a billion
feathers is light.
– Each member of the orchestra is
excellent, so the orchestra is
excellent.
– Each player on this basketball
team is an excellent athlete.
Therefore, the team as a whole is
excellent.
– Every atom in my body is
invisible. Therefore, I am
invisible.
– Each brick in this building is
rectangular in shape. Ergo, this
building must be rectangular in
shape.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
183
Division
• What is true of the
whole is also true of the
parts of the whole thing
• Taking individually what
should be taken
collectively
• The parts are these
because the whole is
this
• E.g.
– Salt is a nonpoisonous
compound. Therefore, its
component elements, sodium
and chlorine, are non-
poisonous.
– The senate passed the RH
Law. Ergo, every member of
the senate is in favor to it.
– Humans are the only animals
capable of philosophical
thinking. Thus, every person
is capable of philosophical
thinking.
– Since a nation is powerful,
every individual citizen of
that nation is powerful.02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
184
Accent
• Arises from the mistaken
interpretation of a
statement but the mistake
is due to the ambiguity in
the way the statement is
spoken
• The arguer illegitimately
stresses one or more words
in the given statement and
then proceeds to draw a
conclusion based on the
resultant interpretation
• E.g.
– Woman without her
man is useless.
– Recycle clothes and
waste paper.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
185
Prosody
• Contains a word that is:
– Misleading
– Confusing
• E.g.
– Thou shall not covet thy
neighbor's wife.
However, Mr. Santos is
not my neighbor. Ergo, I
can covet his wife.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
186
Figure of Speech
• Argues from the
construction of one
word to the form and
the construction of
another
• E.g.
– Insecure is contradictory of
secure. Insincere is also the
contradictory of sincere.
Ergo, inflammable is the
contradictory of flammable.
– Anybody restless is not
restful. Anybody careless is
not careful. Ergo, anybody
helpless is not helpful.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
187
Informal Fallacies
• Fallacies of Relevance
– Overlooks the fact
– No connection between
the premises and the
conclusion
– Argument relies on
premises that are not
relevant to its conclusion
and ergo cannot
establish its truth
• Material Fallacies
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
188
Argumentum ad baculum
• Appeal to force
– Use of threat
• physical or psychological
– Physical force or moral
pressure rather than the
merit of the point at issue
– Discourse of power
– Pointing out their powers
over you
– Warning you of the bad
consequences of refusing to
accept their argument
• E.g.
– Thus there is ample
proof of the truth of the
Bible. All those who
refuse to accept that
truth will burn in Hell.
– Ladies and gentlemen of
the jury, if you do not
bring in a verdict of
guilty, you may be this
killer’s next victim!
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
189
Argumentum ad baculum
• Appeal to force
– Use of threat
• physical or psychological
– Physical force or moral
pressure rather than the
merit of the point at issue
– Discourse of power
– Pointing out their powers
over you
– Warning you of the bad
consequences of refusing to
accept their argument
• E.g.
– Be home by nine tonight
or you can forget about
the increase in
allowance next week.
– You better agree to my
proposal or you won't
see your family
anymore.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
190
Argumentum ad baculum
• Appeal to force
– Use of threat
• physical or psychological
– Physical force or moral
pressure rather than the
merit of the point at issue.
– Discourse of power
– Pointing out their powers
over you
– Warning you of the bad
consequences of refusing to
accept their argument.
• E.g.
– You have just heard the
new policies in our
company. They are
effective immediately.
Anyone who disagrees
may now resign. The
portal of the company is
open.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
191
Argumentum pansarilum
• Argument to one’s own
advantage
– Offer would be heed
unless advantage will be
given regardless of
morality
• E.g.
– I will pay for your
mother’s hospital bill
provided that we will
sleep together tonight
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
192
Argumentum ad misericondiam
• Appeal to pity
– Causes sympathy
– Pleading for mercy and
disregarding the point in
argument
– Pity or sympathy must
be irrelevant to the
issue
• Relevant
– Hungry beggar who
begs for food
– A man who on bended
knees appeals to a
criminal to spare his life
• E.g.
– We cannot condemn this
man because he is the
only one that supports
his family.
– I did not murder my
mother and father with
an axe! Please don't find
me guilty; I'm suffering
enough through being
an orphan.
– Imelda Marcos cries over
jury on Yamashita trial.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
193
Argumentum ad misericondiam
• Appeal to pity
– Causes sympathy
– pleading for mercy and
disregarding the point in
argument
– Pity or sympathy must
be irrelevant to the
issue
• Relevant
– Hungry beggar who
begs for food
– A man who on bended
knees appeals to a
criminal to spare his life
• E.g.
– A student should be
given a passing grade
because he is soon to
graduate, or because if
he fails the course his
parents would disown
him.
– Vote for this candidate
because he has already
put in a lot of money
and heartache in the
campaign.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
194
Argumentum ad misericondiam
• Appeal to pity
– Causes sympathy
– Pleading for mercy and
disregarding the point in
argument.
– Pity or sympathy must
be irrelevant to the
issue
• Relevant
– Hungry beggar who
begs for food
– A man who on bended
knees appeals to a
criminal to spare his life
• E.g.
– I hope you could add
more compassion in
your heart by letting me
pass in this bar
examination. Anyway, I
am already old. To retire
as a full-pledge lawyer is
all I dream of.
– Please accept me to
work in your company. I
have 5 children to feed
and my wife is bed
ridden.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
195
Argumentum ad crumenam
• Believing that money is
a criterion of
correctness
• Those with more money
are more likely to be
right
• E.g.
– Microsoft software is
undoubtedly superior;
why else would Bill
Gates have gotten so
rich?
– Apple must be the best
manufacturer of quality
gadgets, why else would
it be so expensive?
– Give me a passing mark
Sir, and we will talk
about the payment.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
196
Argumentum ad lazarum
• Lazarus
– Jesus raised from being
dead
• Assuming that someone
poor is sounder or more
virtuous than someone
who's wealthier
• E.g.
– Priests are more likely to
possess insight into the
meaning of life, as they
have given up the
distractions of wealth.
– Tenants of Hacienda
Luisita should be given a
parcel of land from the
vast land of Cojuanco
because they have work
hard on it.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
197
Argumentum ad populum
• Appeal to the people or
appeal to emotion
– Enthusiasm and
emotional support
– Attempts to win popular
assent using emotive
language
– Mobilizing public
sentiment
– Direct or Indirect
• E.g.
– Legalize cockfighting
because many people
are engaging in it
anyway.
– The constitution is
defective because many
people want it to be
amended.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
198
Argumentum ad populum
• Direct
– Excite the emotion and
enthusiasm of the crowd
– Arouse a kind of mob
mentality
– Employs emotional
charge phraseology
• E.g.
– Political campaigns
• Iboto si Jingoy Estrada,
Anak ng Ama ng masa,
Anak ng bawat masa.
– Slogans
– Labels
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
199
Argumentum ad populum
• Indirect
– Appeal is addressed to
one or more individuals
separately
• E.g.
– Bandwagon
• 9 out of 10 Moms trust
Lactum. You will be left
behind if you do not use the
product.
– Vanity
• “Only Belo touches my skin.”
– Kris Aquino
– Snobbery
• An apple gadget is not for
everyone. If you think you
belong to the select few, this
distinguished smart phone is for
you!
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
200
Argumentum ad antiquitatem
• Antique
– Old
• Asserting that
something is right or
good simply because it's
old
• That's the way it's
always been
• E.g.
– For thousands of years
Christians have believed in
Jesus Christ. Christianity must
be true, to have persisted so
long even in the face of
persecution.
– UST must be the best
institution for being the
oldest in Asia.
– UIC must be guided by the
holy spirit because it stands
for a century.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
201
Argumentum ad novitatem
• Novitiate
– New
• Asserting that
something is better or
more correct simply
because it is new
• E.g.
– The Clash of Clans is way
cooler than Super Mario
because it was just in
market last week.
– Kia vehicles are more
durable than Toyota
vehicles because it is the
newest brand in the
market.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
202
Poisoning the well
• No chance has the
second man got if the
first man calls him a liar
before he even begins
talking
• E.g.
– Two men are having a
debate. The first one
gets up and says, 'My
opponent is a notorious
liar. You can't believe a
word that he is going to
say.'
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
203
Argumentum ad hominem
• Attack against the person
– Attack is not at the
conclusion of an opponent
but at the person of the
opponent himself
– Attack upon the person
rather than the persons’
ideas.
– What he says should not be
believed because of his
character flaw
– Attacking the person instead
of proving or disproving the
point at issue
• Abusive
• Circumstantial
• Tu quoque
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
204
Argumentum ad hominem
• Abusive
– Attack is directly against
a person seeking to
defame or discredit him
• Opponent possesses a
certain undesirable or
negative characteristic
• Opponents’ words or
abilities are not to be
trusted because of that
characteristic
• E.g.
– Well now, you have all
heard Professor Clark
tell us about the theory
of evolution. But I am
not surprised that he
neglected to tell you
that he is a godless
atheist! How can this
man speak the truth, I
ask you?
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
205
Argumentum ad hominem
• Circumstantial
– Opponent has self-
centered interest on the
topic
• E.g.
– The mall industry lobbyists
have been arguing that tax
reform is not necessary. But
just remember this: it is the
mall industry that stands to
benefit the most if there is no
change in the current tax
laws.
– A student of UM predicts that
the basketball team of ADDU
will win the championship
match. A fellow student of
UM might raise his eyebrows
and ask him, "Where does
your loyalty belong to,
anyway?"02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
206
Argumentum ad hominem
• Tu quoque
– Shifting the burden of guilt
– One defends oneself by
accusing the attacker of
usually similar wrongdoing.
– “Two wrongs do not make a
right” so that even if the
arguer is right in attacking his
accuser, he has not defended
himself against the charge
– Character of an individual is
logically irrelevant to the
truth or falsehood of what
the person says
– May persuade by the
psychological process of
transference
• E.g.
– Yes, I admit, I cheated on
you last night. But you
also cheated on me
before.
– You say I’m not pretty?
Well, you’re not pretty
as well. How can you be
in the position to say
that?
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
207
Argumentum ad vercundiam
• Appeal to misplaced or
inappropriate authority
– Claimant is not
authorized to discuss the
subject matter
– Based not on the
intrinsic merits of the
claim but on the prestige
or fame of the person
endorsing the claim
– Appeal to authority with
respect to matters
outside his specialization
• E.g.
– How can that definition of
love be questioned, criticized
or doubted when it was
Blaise Pascal, a known
mathematician who gave
that.
– My assignment in Logic is not
wrong. Miss Rowling, my
English teacher who is known
internationally as a novelist,
confirmed my answer.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
208
Critique on Argumentum ad vercundiam
by Prof. Sam Bernales, Jr.
• Defending the
misplaced or
inappropriate authority
– Claimant may not be an
expert to discuss the
subject matter but the
argument may be
accepted based on the
person’s passion on the
subject matter.
• E.g.
– Giorgio Tsoukalos of Ancient
Aliens, History Channel,
discusses about the presence
of Aliens in Ancient History of
the World. Giorgio Tsoukalos
is a graduate of Bachelor of
Arts in Mass Communication
major in Sports
Communication. However, he
still merited by the
prestigious History Channel
based on his enthusiasm on
the subject.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
209
Argumentum ad ignorantiam
• Appeal to ignorance
– Proposition is true
• because it has not been
proved false
– Proposition is false
• because it has not been
proved true
– Lack of evidences
• E.g.
– Well, I have examined all the
arguments for the existence of
God, and I have seen that none
of them proves that God exists.
That is reason enough for me:
there is no God!
– Angela Frank is a paragon of
honesty because she never
cheats.
– I am sure that the students have
understood the instructions
perfectly well because no one
raised a hand to ask anything on
my lesson.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
210
Dicto simpliciter
• Accident
– A general rule is applied
wrongly to a specific
case
– From general to
particular
• E.g.
– Jogging is good for the health.
Ergo, a newly-heart-operated
patient should always jog for
good health.
– Freedom of speech is a
constitutionally guaranteed
right. Therefore, that radical
communist should not be
arrested for his speech that
incited that riot last week.
– All good soldiers should obey
their superiors' orders.
Therefore, they should also
obey the captain even if he is
exceedingly in authority.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
211
Dicto simpliciter
• Accident
– A general rule is applied
wrongly to a specific
case
– From general to
particular
• E.g.
– One has to tell the truth
always. Thus, if a murderer
confesses his crime to a
priest, it is but proper for the
priest to reveal the truth to
the authority.
– Customer is always right.
Therefore, the cashier should
return my money because I
changed my mind after
purchase.
– A good student abides the
teacher. Ergo, a beautiful
student should abide the
teacher who implies indecent
favor.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
212
Dicto simpliciter
• Accident
– A general rule is applied
wrongly to a specific
case
– From general to
particular
• E.g.
– Killing is immoral. Ergo,
soldiers and policemen
should not kill in the face of
threat.
– Households should obey their
masters. Ergo, domestic
helpers should obey their
masters imposing sexual
assault.
– Every citizen has the right to
bear arms. Ergo, Sisa, who
has been declared insane,
should not be disarmed.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
213
Dicto simpliciter
• Accident
– Accident is given more
emphasis rather than
the Essence
• E.g.
– Mr. Estrada is not my
father. My father is not a
drunkard, a womanizer
and a gambler.
– You are not my
boyfriend. I have no
cheating boyfriend.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
214
Converse accident
• Hasty generalization
– Conclusion is drawn out
of the sample that is not
a representative of the
group
– One moves carelessly or
too quickly from a single
case to a broad
generalization
– From particular to
general
• E.g.
– I know that Philosophers are
weird and odd people
because I have seen that in
my teachers behavior.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
215
Post hoc
• False Cause
– The link between
premises and conclusion
depends on some
imagined causal
connection that does
not exist
– Superstitious beliefs or
Oversimplification
• E.g.
– It rains whenever she arrives,
ergo to avoid rains we must
not invite her to come over.
– During the past two months,
every time that the
cheerleaders wore blue
ribbons in their hair, the
basketball team was
defeated. Therefore, to
prevent defeats in the future,
the cheerleaders should get
rid of those blue ribbons.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
216
Post hoc
• False Cause
– Superstitious beliefs
• Cultural
• Pass on from one
generation to another
• E.g.
– He met an accident
because it was Friday
the 13th
.
– A black cat crossed my
path and later I tripped
and sprained my ankle.
It must be that black cats
are really bad luck.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
217
Post hoc
• False Cause
– Oversimplification
• An arguer explains the
occurrence of some event
or phenomenon in terms
of one or more of its least
important causes
• E.g.
– I blame the television media
for the epidemic of hijackings,
kidnappings, and other acts
of terrorism. If we would
stop televising terrorist acts,
they would stop.
– The divorce rate in America
has been climbing steadily. At
the same time, the number of
juveniles getting into trouble
with the law has shoot up.
Something must be done
about the divorce rate since it
is causing such a rapid
increase in juvenile
delinquency.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
218
Non-sequitor
• It does not follow
– Conclusion does not
necessarily follow from
our premises
• E.g.
– I love you therefore it
follows that you love
me.
– She is the most beautiful
student in this University
ergo she should be given
a scholarship.
– He goes to Church
everyday ergo it is
impossible for him to do
corruption.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
219
Ignoratio elenchi
• Ignorance of the proof
– Irrelevant conclusion
– Missing the point
• Draws a conclusion that
misses the point entirely
• E.g.
– Crimes of theft and robbery
have been increasing at an
alarming rate lately. The
conclusion is obvious: we
must reinstate the death
penalty immediately.
– The man is currently suffering
from amnesia and has no
recollection whatever of the
event of the past two weeks.
We can only conclude that he
did not commit the crime of
murdering his neighbor, as he
has been accused of doing.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
220
Contradictory Premise
• Premises contradict
each other
• E.g.
– If God can do anything,
can He make a stone so
heavy that He won't be
able to lift it? But if He
can do anything, He can
lift the stone.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
221
Genetic
• Taking the origin as
evidence
• E.g.
– Ferdinand Marcos Jr.
was raised by his Father
who declared Martial
Law. It is clear that upon
winning the Presidential
election, Ferdinand
Marcos Jr. will also
declare Martial Law.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
222
False Dilemma
• 1 of the 2 claims was
proven false. Therefore,
the other is doubtless
true.
• Jejomar Binay and Mar
Roxas are both running
for Presidency. Jejomar
Binay was accused of
corruption. Therefore
we should vote for Mar
Roxas for President.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
223
Petitio principii
• Begging the question
– Circular argument
• The premise of the
argument is simply a
reinstatement of the
conclusion
• E.g.
– Birds know how to fly because
they have wings and wings can
make them fly.
– Philosophers are highly
intelligent individuals because if
they were not highly intelligent
they would not be philosophers.
– The Bible asserts that God exists.
The Bible is the divine word of
God. Therefore, God exists.
– "Why are you here?" "Because
I'm not there.“
– Declarative sentence is the
sentence that declares.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
224
Complex question
• A question is asked in
such a way as to
presuppose the truth of
some assumption
buried in that question
• 1 Question (Actually 2
questions) = 1 Answer
• E.g.
– Have you stopped
cheating on your
girlfriend?
– Do you still cheat on
exams?
– Is this the knife you used
to kill the victim?
– Where did you hide the
money you stole?
– What did you use to wipe
your fingerprints from the
gun?
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
225
False analogy
• The analogy is not strong
enough to support the
conclusion that is drawn
• The assumption is that if
two or more things are alike
in some respects, they are
alike in some other respect
• Analogy or resemblance is
not sufficient to warrant the
conclusion
• E.g.
– Bobby’s new car is bright
blue, has leather
upholstery, and is
expensive. Crowley’s
new car is also bright
blue and has leather
upholstery. Therefore, it
is also expensive.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
226
Hypothesis Contrary to Fact
• Hypothesis that is not
true and then draw any
supportable conclusions
from it
• E.g.
– If Madame Curie had not
happened to leave a
photographic plate in a
drawer with a chunk of
pitchblende, the world
today would not know
about radium.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
227
Slippery slope
• Claims that a certain
event will set off a chain
reaction, leading in the
end to some
undesirable
consequence, yet there
is no sufficient reason
to think that the chain
reaction will actually
take place
• E.g.
– Attempts to outlaw
pornography threaten basic
civil rights and should be
summarily abandoned. If
pornography is outlawed,
censorship of newspapers
and news magazines is only a
short step away. After that
there will be censorship of
textbooks, political speeches,
and the content of lectures
delivered by university
professors. Complete mind
control by the central
government will be the
inevitable result.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
228
Slippery slope
• Claims that a certain
event will set off a chain
reaction, leading in the
end to some
undesirable
consequence, yet there
is no sufficient reason
to think that the chain
reaction will actually
take place
• E.g.
– Studying philosophy is a
dangerous thing to do.
It makes you critical.,
which in turn makes you
skeptical of your
religious beliefs. And
once you have begun to
lose faith in your
religion, it is a small step
to atheism and
immorality, and a life of
immorality is damned.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
229
Red herring
• The arguer diverts the attention
of the reader or listener by
addressing a number of
extraneous issues and ends by
presuming that some conclusion
has been established
• The fallacy got its name from the
practice of using a herring, a
particularly smelly fish when
cooked, to divert hunting dogs
from the scent of a fox
• Directing attention away from
the issue to other seemingly
related issues
• E.g.
– Friends and neighbors I urge you
to defeat the proposal to make
jail sentences mandatory for
drunk drivers. My opponent
claims that it will reduce the
number of accidents caused by
drunk drivers. But if we really
want to reduce traffic accidents,
then we should stand behind
those men and women whose
chief responsibility is our safety.
I am referring of course, to our
valiant police officers, what we
need to do is increase their
salaries, beef up the police force,
and, most importantly, stop
butting into their business with
troublesome people.
02/10/17 03:00 AM
Critical Thinking and Correct Reasoning
Prof. Sam
Bernales, Jr.
230
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning
Logic: Critical Thinking and Correct Reasoning

More Related Content

What's hot (20)

Hypothetical Syllogism
Hypothetical SyllogismHypothetical Syllogism
Hypothetical Syllogism
 
Logic.ppt.
Logic.ppt.Logic.ppt.
Logic.ppt.
 
Logic - Three mental operations
Logic - Three mental operationsLogic - Three mental operations
Logic - Three mental operations
 
Logical Opposition (Social Philosophy and Logic)
Logical Opposition (Social Philosophy and Logic)Logical Opposition (Social Philosophy and Logic)
Logical Opposition (Social Philosophy and Logic)
 
Syllogistic figures
Syllogistic figuresSyllogistic figures
Syllogistic figures
 
Logic
LogicLogic
Logic
 
Logic hand outs#4
Logic hand outs#4Logic hand outs#4
Logic hand outs#4
 
LOGIC: Ideas & Terms
LOGIC: Ideas & TermsLOGIC: Ideas & Terms
LOGIC: Ideas & Terms
 
Idea
IdeaIdea
Idea
 
Inversion
InversionInversion
Inversion
 
Division of logic
Division of logicDivision of logic
Division of logic
 
Logic for Freshmen-Collegiate
Logic for Freshmen-CollegiateLogic for Freshmen-Collegiate
Logic for Freshmen-Collegiate
 
Nature of the idea
Nature of the ideaNature of the idea
Nature of the idea
 
Philosophers
PhilosophersPhilosophers
Philosophers
 
Eduction (ph1)
Eduction (ph1)Eduction (ph1)
Eduction (ph1)
 
Syllogism
SyllogismSyllogism
Syllogism
 
Categorical propositions
Categorical propositionsCategorical propositions
Categorical propositions
 
Philosophy,logic and its kind,inductive and deductive reasoning ppt
Philosophy,logic and its kind,inductive and deductive reasoning pptPhilosophy,logic and its kind,inductive and deductive reasoning ppt
Philosophy,logic and its kind,inductive and deductive reasoning ppt
 
Hypothetical proposition
Hypothetical propositionHypothetical proposition
Hypothetical proposition
 
Philosophy 101
Philosophy 101Philosophy 101
Philosophy 101
 

Viewers also liked

LOGIC AND CRITICAL THINKING
LOGIC AND CRITICAL THINKINGLOGIC AND CRITICAL THINKING
LOGIC AND CRITICAL THINKINGtagupaleomark
 
Cauchy riemann equations
Cauchy riemann equationsCauchy riemann equations
Cauchy riemann equationsHanpenRobot
 
Integration in the complex plane
Integration in the complex planeIntegration in the complex plane
Integration in the complex planeAmit Amola
 
Cauchy's integral formula 
Cauchy's integral formula Cauchy's integral formula 
Cauchy's integral formula HanpenRobot
 
Cauchy riemann equations
Cauchy riemann equationsCauchy riemann equations
Cauchy riemann equationssajidpk92
 

Viewers also liked (6)

LOGIC AND CRITICAL THINKING
LOGIC AND CRITICAL THINKINGLOGIC AND CRITICAL THINKING
LOGIC AND CRITICAL THINKING
 
Cauchy riemann equations
Cauchy riemann equationsCauchy riemann equations
Cauchy riemann equations
 
Integration in the complex plane
Integration in the complex planeIntegration in the complex plane
Integration in the complex plane
 
Cauchy's integral formula 
Cauchy's integral formula Cauchy's integral formula 
Cauchy's integral formula 
 
Cauchy riemann equations
Cauchy riemann equationsCauchy riemann equations
Cauchy riemann equations
 
Critical Thinking and Problem Solving
Critical Thinking and Problem SolvingCritical Thinking and Problem Solving
Critical Thinking and Problem Solving
 

Similar to Logic: Critical Thinking and Correct Reasoning

Ethics and Christian Morality with Character Education
Ethics and Christian Morality with Character EducationEthics and Christian Morality with Character Education
Ethics and Christian Morality with Character EducationSam Bernales Jr
 
Introduction to and History of Philosophy
Introduction to and History of PhilosophyIntroduction to and History of Philosophy
Introduction to and History of PhilosophySam Bernales Jr
 
SFU.formative assessment
SFU.formative assessmentSFU.formative assessment
SFU.formative assessmentFaye Brownlie
 
2017 aacr youth day
2017 aacr youth day2017 aacr youth day
2017 aacr youth dayDon Doerres
 
Coquitlam pns.april2012.no pics
Coquitlam pns.april2012.no picsCoquitlam pns.april2012.no pics
Coquitlam pns.april2012.no picsFaye Brownlie
 
Listening Skills
Listening SkillsListening Skills
Listening Skillseph-hr
 
Mi ip week 6 power point_april 2018_gw
Mi ip week 6 power point_april 2018_gwMi ip week 6 power point_april 2018_gw
Mi ip week 6 power point_april 2018_gwbrittneyleanngraves
 
Questioning mat
Questioning matQuestioning mat
Questioning matbedwells
 
Slideshare howtostudy-090407124516-phpapp01
Slideshare howtostudy-090407124516-phpapp01Slideshare howtostudy-090407124516-phpapp01
Slideshare howtostudy-090407124516-phpapp01Lufemuac
 
Personality and Communication - True Colors
Personality and Communication - True ColorsPersonality and Communication - True Colors
Personality and Communication - True ColorsRotary International
 
Personality types
Personality typesPersonality types
Personality typesHosam Kusba
 
Critical thinking and questions goldilocks
Critical thinking and questions goldilocksCritical thinking and questions goldilocks
Critical thinking and questions goldilocksMarinazx
 

Similar to Logic: Critical Thinking and Correct Reasoning (15)

Ethics and Christian Morality with Character Education
Ethics and Christian Morality with Character EducationEthics and Christian Morality with Character Education
Ethics and Christian Morality with Character Education
 
Introduction to and History of Philosophy
Introduction to and History of PhilosophyIntroduction to and History of Philosophy
Introduction to and History of Philosophy
 
2018 tamid sshw
2018 tamid sshw2018 tamid sshw
2018 tamid sshw
 
SFU.formative assessment
SFU.formative assessmentSFU.formative assessment
SFU.formative assessment
 
2017 aacr youth day
2017 aacr youth day2017 aacr youth day
2017 aacr youth day
 
Coquitlam pns.april2012.no pics
Coquitlam pns.april2012.no picsCoquitlam pns.april2012.no pics
Coquitlam pns.april2012.no pics
 
Listening Skills
Listening SkillsListening Skills
Listening Skills
 
Listening skills
Listening skillsListening skills
Listening skills
 
Multiple intelligence
Multiple intelligenceMultiple intelligence
Multiple intelligence
 
Mi ip week 6 power point_april 2018_gw
Mi ip week 6 power point_april 2018_gwMi ip week 6 power point_april 2018_gw
Mi ip week 6 power point_april 2018_gw
 
Questioning mat
Questioning matQuestioning mat
Questioning mat
 
Slideshare howtostudy-090407124516-phpapp01
Slideshare howtostudy-090407124516-phpapp01Slideshare howtostudy-090407124516-phpapp01
Slideshare howtostudy-090407124516-phpapp01
 
Personality and Communication - True Colors
Personality and Communication - True ColorsPersonality and Communication - True Colors
Personality and Communication - True Colors
 
Personality types
Personality typesPersonality types
Personality types
 
Critical thinking and questions goldilocks
Critical thinking and questions goldilocksCritical thinking and questions goldilocks
Critical thinking and questions goldilocks
 

Recently uploaded

Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxryandux83rd
 
Objectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxObjectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxMadhavi Dharankar
 
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQ-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQuiz Club NITW
 
An Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPAn Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPCeline George
 
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDecoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDhatriParmar
 
4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptxmary850239
 
Indexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfIndexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfChristalin Nelson
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationdeepaannamalai16
 
How to Make a Duplicate of Your Odoo 17 Database
How to Make a Duplicate of Your Odoo 17 DatabaseHow to Make a Duplicate of Your Odoo 17 Database
How to Make a Duplicate of Your Odoo 17 DatabaseCeline George
 
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxCLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxAnupam32727
 
Integumentary System SMP B. Pharm Sem I.ppt
Integumentary System SMP B. Pharm Sem I.pptIntegumentary System SMP B. Pharm Sem I.ppt
Integumentary System SMP B. Pharm Sem I.pptshraddhaparab530
 
How to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineHow to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineCeline George
 
ClimART Action | eTwinning Project
ClimART Action    |    eTwinning ProjectClimART Action    |    eTwinning Project
ClimART Action | eTwinning Projectjordimapav
 
ARTERIAL BLOOD GAS ANALYSIS........pptx
ARTERIAL BLOOD  GAS ANALYSIS........pptxARTERIAL BLOOD  GAS ANALYSIS........pptx
ARTERIAL BLOOD GAS ANALYSIS........pptxAneriPatwari
 

Recently uploaded (20)

Plagiarism,forms,understand about plagiarism,avoid plagiarism,key significanc...
Plagiarism,forms,understand about plagiarism,avoid plagiarism,key significanc...Plagiarism,forms,understand about plagiarism,avoid plagiarism,key significanc...
Plagiarism,forms,understand about plagiarism,avoid plagiarism,key significanc...
 
Introduction to Research ,Need for research, Need for design of Experiments, ...
Introduction to Research ,Need for research, Need for design of Experiments, ...Introduction to Research ,Need for research, Need for design of Experiments, ...
Introduction to Research ,Need for research, Need for design of Experiments, ...
 
Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptx
 
INCLUSIVE EDUCATION PRACTICES FOR TEACHERS AND TRAINERS.pptx
INCLUSIVE EDUCATION PRACTICES FOR TEACHERS AND TRAINERS.pptxINCLUSIVE EDUCATION PRACTICES FOR TEACHERS AND TRAINERS.pptx
INCLUSIVE EDUCATION PRACTICES FOR TEACHERS AND TRAINERS.pptx
 
Spearman's correlation,Formula,Advantages,
Spearman's correlation,Formula,Advantages,Spearman's correlation,Formula,Advantages,
Spearman's correlation,Formula,Advantages,
 
Objectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxObjectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptx
 
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQ-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
 
An Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPAn Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERP
 
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDecoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
 
4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx
 
Indexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdfIndexing Structures in Database Management system.pdf
Indexing Structures in Database Management system.pdf
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentation
 
How to Make a Duplicate of Your Odoo 17 Database
How to Make a Duplicate of Your Odoo 17 DatabaseHow to Make a Duplicate of Your Odoo 17 Database
How to Make a Duplicate of Your Odoo 17 Database
 
Faculty Profile prashantha K EEE dept Sri Sairam college of Engineering
Faculty Profile prashantha K EEE dept Sri Sairam college of EngineeringFaculty Profile prashantha K EEE dept Sri Sairam college of Engineering
Faculty Profile prashantha K EEE dept Sri Sairam college of Engineering
 
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxCLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
 
Integumentary System SMP B. Pharm Sem I.ppt
Integumentary System SMP B. Pharm Sem I.pptIntegumentary System SMP B. Pharm Sem I.ppt
Integumentary System SMP B. Pharm Sem I.ppt
 
How to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineHow to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command Line
 
ClimART Action | eTwinning Project
ClimART Action    |    eTwinning ProjectClimART Action    |    eTwinning Project
ClimART Action | eTwinning Project
 
prashanth updated resume 2024 for Teaching Profession
prashanth updated resume 2024 for Teaching Professionprashanth updated resume 2024 for Teaching Profession
prashanth updated resume 2024 for Teaching Profession
 
ARTERIAL BLOOD GAS ANALYSIS........pptx
ARTERIAL BLOOD  GAS ANALYSIS........pptxARTERIAL BLOOD  GAS ANALYSIS........pptx
ARTERIAL BLOOD GAS ANALYSIS........pptx
 

Logic: Critical Thinking and Correct Reasoning

  • 1. Prof. Sam Bernales, Jr. 02/10/17 03:00 AM 1 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 2. Logic • Logike/ Logia/ Logos – Coined by Zeno the Stoic • Analytics – Prior and Posterior – Study – Reason – Discourse – Study of the fundamental principles which govern the true nature of correct reasoning or inferential thinking. 02/10/17 03:00 AM 2 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 3. Logic • Science and Art of Critical Thinking and Correct Reasoning • Science – Systematized body of Logical Truths and Principles governing correct thinking • Art – Beautiful and Good reasoning – Power to perform certain actions guided by special knowledge and executed with skill 02/10/17 03:00 AM 3 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 4. Logic in Profession • Facilitates in organizing ideas. • Scientists – Scientific Method • Public Speaker – Organization of Idea • Lawyer – Good argument to prove position • Household – Planning and organizing things in house. 02/10/17 03:00 AM 4 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 5. Logic in Profession • Activity – How can I apply Logic in my profession? 02/10/17 03:00 AM 5 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 6. Mind Teaser • Activity – Abstract Reasoning • Inverse the Triangle by moving only 3 balls 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 6
  • 7. Mind Teaser • Activity – Abstract Reasoning • Connect all the spheres in 4 straight uninterupted lines 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 7
  • 8. Activity • Abstract Reasoning 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 8
  • 9. Mind Teaser • Verbal Reasoning – Question • Mayroong 64 na maleta sa eroplano na nasa himpapawid. Kung nahulog ang isa, ilan na lang ang natira? – Answer • 63 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 9
  • 10. Mind Teaser • Verbal Reasoning – Question • Paano ipapasok ang elepante sa loob ng refrigerator sa tatlong paraan? – Answer • 1. Buksan ang refrigerator • 2. Ipasok ang elepante • 3. Isara ang refrigerator 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 10
  • 11. Mind Teaser • Verbal Reasoning – Question • Paano ipapasok and giraffe sa loob ng refrigerator sa apat na paraan? – Answer • 1. Buksan ang refrigerator • 2. Ilabas ang elepante sa refrigerator • 3. Ipasok ang giraffe sa loob ng refrigerator • 4. Isara ang refrigerator 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 11
  • 12. Mind Teaser • Verbal Reasoning – Question • Kaarawan ng haring leon. Lahat ng hayop naroon pero may nawawalang isa. Anong hayop ito? – Answer • Giraffe, naiwan sa loob ng refrigerator 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 12
  • 13. Mind Teaser • Verbal Reasoning – Question • Paano makakatawid sa ilog ang isang babae nang hindi kakainin ng mga buwaya? – Answer • Tatawid lang siya kasi nasa kaarawan ng haring leon ang lahat ng hayop 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 13
  • 14. Mind Teaser • Verbal Reasoning – Question • Habang tumatawid sa ilog ang babae, siya ay namatay. Ano ang dahilan ng kanyang pagkamatay? – Answer • Sa kanya bumagsak yung maleta mula sa eroplano 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 14
  • 15. Mind Teaser • Verbal Reasoning – Question • How many dwarves are there in the story of Cinderella? – Answer • None. It was Snow White who has seven dwarves. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 15
  • 16. Mind Teaser • Verbal Reasoning – Question • Which is heavier, 1kg of Gold or 1kg of Feather? – Answer • There is no heavier between the two. Both of them weights 1kg. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 16
  • 17. Mind Teaser • Verbal Reasoning – Question • Inutusan ka para barilin ang isang target. Ang sabi sayo, kung mata tamaan mo, saka ka babayaran. Tinamaan mo sa noo ang target, pero hindi ka binayaran ng taong nag- utos sayo. Ano ang dahilan bakit di ka binayaran? – Answer • Hindi mo natamaan sa mata ang target. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 17
  • 18. Mind Teaser • Verbal Reasoning – Question • May isang babae na dumalaw sa isang puntod. Noong tinanong siya kung kaanu-ano niya ang nasa puntod and sagot niya, “Ang nanay niya ang nag- iisang anak ng nanay ko.” Kaano ano nya ang nasa puntod? – Answer • Anak 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 18
  • 19. Activity • Verbal Reasoning 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 19
  • 20. Divisions of Logic • Formal (Form) – Rules – Principles • Simple apprehension – Grasp entity or reality • Judgment – Compares two ideas based on relation • Reasoning – Abstraction • Material (Matter) – Substance of reasoning 02/10/17 03:00 AM 20 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 21. Exempli Gratia All senators are politicians. No senators are congressmen. X Ergo, no congressmen are politicians. Formally Correct Materially Wrong All nurses are health- care professionals. Some nurses are Filipinos. Ergo, some Filipinos are health-care professionals. Formally Correct Materially Correct 02/10/17 03:00 AM 21 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 22. Formal Logic • Every cat is an animal • Every tiger is an animal • Ergo, every tiger is cat Formally Wrong Materially Wrong 02/10/17 03:00 AM 22 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 23. Formal Logic • Every cat is animal • Every pig is animal • Ergo, every pig is cat. Formally Wrong Materially Wrong 02/10/17 03:00 AM 23 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 24. Formal Logic • Every animal is four legged substance • Some table is animal • Ergo, every table is four-legged substance. Formally Correct Materially Wrong 02/10/17 03:00 AM 24 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 25. Structure of Logic External Expressions/ Significations Mental Operations Term/ Concept Simple Apprehension Proposition Judgment Syllogism/ Fallacy/ Debate Reasoning/ Argument 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 25
  • 26. Terms • Terms – Signs of concepts – Instrumental signs – Expression of an idea – Thought – Concept – Mental Proposition – Mental Argumentation 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 26
  • 27. Terms according to Structure • Simple – Consist only one word • Skunk • Complex – Consists of a group of words that signify one thing • The black little cat-like animal with the white stripe down its back is a skunk 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 27
  • 28. Terms according to Essence • Significant – Signifies the quiddity (whatness) or nature of the thing they stand for • Man, Dog • Non-significant – merely point out things without signifying their quiddities or nature • This, That, Those 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 28
  • 29. Terms According to Components • Simple – Only one feature • Book • Compound – Several features • Human Person 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 29
  • 30. Terms According to Comprehension • Concrete – Expresses something which has attributes that are capable of being perceived through the senses. • ball, can, desk, stone • Abstract – expresses something as separated from any single object. It denotes the general attributes of many objects. • When I sit next to you, my heart beats definitely faster. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 30
  • 31. Terms According to Comprehension • Abstractive – Creates a meaning out of own experience • Great experience • Being whole • Happiness • Intuitive – Requires presence of an object • Hot coffee • Warmth of day 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 31
  • 32. Terms According to Comprehension • Absolute/ Privative – No relation to other idea • God • Relative – Explicit relation to other idea • Teacher and Student • Master and Slave 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 32
  • 33. Terms According to Comprehension • Complete – Expresses all features • Dog • Incomplete – Expresses only some features • Dog as an animal 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 33
  • 34. Terms according to Comprehension • Generic – Common feature • Being • Paracetamol • Specific – Distinctive feature • Rational • Biogesic 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 34
  • 35. Terms according to Extension • Common – General term • Professor • Individual – One object • Proper Name – Prof. Dumbledore • Particular Circumstance – Head Professor of Hogwarts • Demonstrative Pronoun – This Professor 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 35
  • 36. Terms according to Extension • Distributive – Essence of entities singularly • Fish • Ant • Collective – Essence of entities as group • School of Fishes • Colony of Ants 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 36
  • 37. Terms according to Extension • Universal – represents not only a class as a whole but also each member of the class • table, chair, stone • Collective – represents a number of things constituting a unit-group or whole • family, choir, band, team • Particular – represents only a part of the universal whether it is definite or indefinite • three kings, few guests • Singular – represents a single object • My father, this book 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 37
  • 38. Activity • Topic – Terms according to Extension • Instruction – Identify the term according to extension: • Universal • Collective • Particular • Singular 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 38
  • 39. Inverse Relationship between Comprehension and Extension COMPREHENSION (S-U) SUPPOSITION EXTENSION (U-S) INTENSION SUBSTANCE Substance Angel, Mineral, Plant, Brute, Man BODY Corporeal Substance Mineral, Plant, Brute, Man ORGANISM Animate Corporeal Substance Plant, Brute, Man ANIMAL Sentient Animate Corporeal Substance Brute, Man MAN Rational Sentient Animate Corporeal Substance Man 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 39
  • 40. Inverse Relationship between Comprehension and Extension • Comprehension – Supposition – Stands for a definite one of the various things it can stand • Chair – Five letter word – Furniture – Chairman • Extension – Intension – Ascribed meaning • Giving example 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 40
  • 41. Activity • Topic – Inverse Relationship between Comprehension and Extension • Each number contains a pair of terms. • Identify whether the terms are ordered according to Comprehension or Extension. • Arrange the following according to the order of Extension • Comprehension • Extension 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 41
  • 42. Terms according to Meaning • Univocal – Same meaning • Human as Person and Human as Person • Analogous – Related meaning – Depends on application • Falling as motion and Falling as in love • Equivocal – Different meaning • Mouse of computer and Mouse in the hole of the house 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 42
  • 43. Activity • Topic – Terms according to meaning • Instruction – 1. Classify the italicized term in the following sentences according to meaning. • Univocal • Analogous • Equivocal 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 43
  • 44. Terms according to Perfection • Precise – Exact manner • Triangle – Right Triangle • Imprecise – Not exact manner • Acute Triangle 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 44
  • 45. Terms according to Perfection • Clear – Distinct manner • Man as rational being • Obscure – Vague – Indistinct manner • Man as talking animal 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 45
  • 46. Terms according to Perfection • Adequate – Man as rational being • Inadequate – Man as being 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 46
  • 47. Terms according to Origin/ Formation • Immediate/ Intuitive – Direct observation of things • Water is liquid • Ice is solid • Mediate/ Abstracted – Matters of Faith • Man derives from ape • God is the beginning of all things 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 47
  • 48. Terms according to Origin/ Formation • Explicit – Directly expressed • “I love you.” • Implicit – Directly implied – Matter of presumption • Kiss, Hug 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 48
  • 49. Terms according to Origin/ Formation • Ideal/ Mental – Mind envisions • Heaven on earth • Classless society • Subjective/ Arbitrary – Personal thinking – Judgment of man • Man came from Adam • Real/ Objective – Factual reality • Woman Lawyer 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 49
  • 50. Terms according to Relation • Identical – Same idea • Human Person and Rational being • Equivalent – Not the same formal features • Salt and Sodium Chloride 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 50
  • 51. Terms according to Relation • Pertinent – Related to each other • Rationality and Learning • Freedom and Responsibility • Authority and Responsibility • Right and Obligation • Impertinent – Not related to each other • Intellect and Gender • Age and Maturity • Wisdom and Race 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 51
  • 52. Terms according to Relation • Similar – Same extension but different comprehension • Coffee and Barako • Writer and Journalist • Compatible – Coexist in a subject • Beauty and Brain • Tall, Dark and Handsome • Reason and Faith • Incompatible – That cannot coexist • Sin and Holiness • Health and Sickness • Wisdom and Foolishness • Division of Incompatible Terms – Contradictory • Extremely opposite – Living and Dead – Hot and Cold – High and Low – Contrary • Opposed in certain order – Rich and Poor – Tall and Short – Privative • Concept and its defect – Sight and blindness – Hearing and deafness – Correlative • Mutual relation – Master and Servant – Husband and Wife – Student and Teacher 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 52
  • 53. Terms according to Object • Real/ Concrete – Expresses something that has existential actuality • Chair, Table • Abstract/ Logical – Conceptual device to facilitate learning • Democracy • Arbitrary/ Imaginary – No correspondent reality • Spiderman, Flying Carpet • Metaphorical – Stand for an allied meaning • Lamb of God 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 53
  • 54. Activity • Topic – Terms according to Comprehension, Relation and Object • Instruction – Identify the term according to comprehension, relation and object: • Compatible or Incompatible • Absolute/ Privative or Relative • Arbitrary or Real • Concrete or Abstract 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 54
  • 55. Terms according to Quality • Positive Form, Positive Meaning (+) (+) – Life, Truth, Freedom • Positive Form, Negative Meaning (+) (-) – Happy-go-lucky • Negative Form, Negative Meaning (-) (-) – Illegal, Impolite • Negative Form, Positive Meaning (-) (+) – Immortal, Infinite 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 55
  • 56. Activity • Topic – Terms according to Quality • Instruction – Classify the following terms according to Quality • (+) (+) – Positive Form, Positive Meaning • (+) (-) – Positive Form, Negative Meaning • (-) (-) – Negative Form, Negative Meaning • (-) (+) – Negative Form, Positive Meaning 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 56
  • 57. Predicaments • Substance • Man, Dog, Plant • Accident – Quantity • 50 kg.; 100 pesos; 25 ft. long – Quality • intelligent, red, hot, strong, healthy, beautiful – Relation • father, husband – Action/ Activity • running, walking, dancing, driving – Passion • being killed, was shot, are burned, to be lifted – Time • now, today, at 8 pm, next week, noon, morning – Place • here, in the office, Davao, Manila, in the air – Posture/ Position • lying, standing, sitting – Habit/ Possession • in red gown, covered with lace , dressed, armed 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 57
  • 58. Activity • Topic – Predicaments • Instructions • Identify the italicized terms according to its category/ predicaments. • Substance • Quantity • Quality • Relation • Action • Passion • Time • Place • Posture • Habit 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 58
  • 59. Predicables • Genus – Specie in a class • E.g. Triangle is a polygon • Specific Difference – Differences of the specie from others • E.g. Triangle is three-sided • Species – complete essence of a thing • E.g. Triangle is a three-sided polygon • Accident – Something that attributes the thing by contingency • E.g. Acute Triangle • Property – Attribute • E.g. Triangle has 25 Degrees on each side 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 59
  • 60. Judgment • Judgment – Mental operation that pronounces the agreement or disagreement between two ideas – E.g. • Square and Polygon – Square is a Polygon • Table and Chair – Table is not a Chair 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 60
  • 61. Proposition • Subject statement – True or False • Logic is the study of the principles of correct reasoning. • Being a president is like riding a tiger. • Charles Dickens wrote Romeo and Juliet. 02/10/17 03:00 AM 61 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 62. Proposition • Subject statement – Affirmed or Denied • God exists. • Atlantis uncovered. 02/10/17 03:00 AM 62 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 63. Proposition • Subject statement – affirm or deny the attribute of a subject. • A dog is an animal. • A dog is not a cat. 02/10/17 03:00 AM 63 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 64. Proposition • Subject statement – affirm or deny the relationships, connections between member propositions. • If it is raining, the ground is probably wet. 02/10/17 03:00 AM 64 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 65. Activity • Topic – Proposition • Instruction – 1. Identify which of the following is a Proposition and which is not. – 2. Write P if the statement is proposition and N if it is not. – 3. Write the answer on the blank provided in each sentence. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 65
  • 66. Activity • Topic – Proposition • Instruction – Establish whether this proposition is true or false. – Explain • True • False • True and False • I refuse to answer True or False 02/10/17 03:00 AM 66 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 67. Types of Proposition • Causal • Modal • Inferential • Simple • Compound • Existential • Non-existential • Categorical • Hypothetical 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 67
  • 68. Elements of Proposition • Subject – Something that is being talked about in the Proposition – Something that is denied or affirmed • Copula – Linking verb – Tense • Predicate – Something that talks about the Subject – Affirmed or denied by the Subject 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 68
  • 69. Structure of Proposition • Quantifier (Form) – All • Subject (Matter) – students majoring in philosophy • Copula (Form) – are • Predicate (Matter) – required to take Metaphysicsand Epistemology 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 69
  • 70. Quantifiers • Universal Quantifier – All ( Affirmative ) – Every ( Affirmative ) – Any ( Affirmative ) – No ( Negative ) – None ( Negative ) • Particular Quantifier – Some – At least one – Most – Almost all – The majority 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 70
  • 71. Categorical Proposition • A (Universal-Affirmative) • All S are P – All politicians are honorable men. • I (Particular-Affirmative) • Some S are P – Some politicians are honorable men. • E (Universal-Negative) • All S are not P – All politicians are not honorable men. • O (Particular-Negative) • Some S are not P – Some politicians are not honorable men. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 71 Affirmative Negative Universal A E Particular I O
  • 72. Double Negation • Negative + Negative = Positive • Offset Rule • Bullet and Train Method • E.g. – No man is not mortal by nature. – He who did not vote for Roxas last national election was not convinced of his leadership. • E.g. – No dogs that are without pedigrees are candidates for the blue ribbon in official dog shows. – Not all ordained ministers are not holy. – Nothing that is material is indestructible. – Most sins are not unforgivable. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 72
  • 73. Modal Propositions • (A) Necessary Mode – An absolute being must exist. – It is necessary for cats to purr. • (E) Impossible Mode – Angels cannot be mortals. – It is impossible for squares to be circulars. • (I) Possible Mode – This car can run 300 mph. – It is possible for believer to become saints. • (O) Unnecessary Mode – It is not necessary for God to be creator just to become God. – It is contingent for tables to have four legs. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 73
  • 74. Quality of Proposition • Not all – Particular Negative • Last but not the least – Affirmative 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 74
  • 75. Hypothetical Proposition • Disjunctive Proposition – Either-or (+) (-) • The will is either free or determined. • Conjunctive Proposition – All cannot be true (-) (-) • You cannot work and play at the same time. • Conditional Proposition – If-then (+) (+) • If a man works, then he deserves the reward of his labor. • Biconditional Proposition – If and only if (+) (+) • You will pass this course if and only if you will study hard. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 75
  • 76. Activity • Topic – Hypothetical Proposition • Instruction – 1. State the correct hypothetical proposition. • Conditional • Biconditional • Conjunctive • Disjunctive 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 76
  • 77. Activity • Topic – Categorical Proposition I • Instruction – 1. Classify the following Proposition according to quantity, quality and symbol. • Quantity – Universal – Particular • Quality – Affirmative – Negative • Symbol – A – I – E – O 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 77
  • 78. Activity • Topic – Categorical Proposition II • Instruction – 1. Give the correct symbol of the following categorical proposition. • A • I • E • O 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 78
  • 79. Inference • Inference – The conclusion is reached – Meanings are already implied in the former • Non-inference – The conclusion is not reached • From the given premise: – The birds are flying south. – She graduated summa cum laude. – Lights are out and their car is gone. – The cat is standing by her dish meowing. • Infer the conclusion: – I suspect they are not home. – She is probably hungry. – Winter must be coming. – She must have studied hard in college. 02/10/17 03:00 AM 79 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 80. Types of Inference • Immediate – Draws conclusion from any proposition • Opposition • Logical Proposition • Eduction – Interchanging the subject and predicate – Putting or removal of negatives • Mediate – Draws conclusion from series of proposition • Categorical Syllogism 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 80
  • 81. Square of Opposites Every S is P No S is P Some S is P Some S is not P 02/10/17 03:00 AM 81 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. • Contrariety – Contraries • Contradiction – Contradictories • Subalternation – Subalterns • Subcontrariety – Subcontraries
  • 82. Laws of Contradiction • Rule: – If A is true, O is false. – If E is true, I is false. – If A is false, O is true. – If E is false, I is true. – If O is true, A is false. – If I is true, E is false. – If O is false, A is true. – If I is false, E is true. – A - All dogs are animals. – O - Some dogs are not animals. – E - No women are married. – I - Some women are married. – O - Some prisoners are not guilty. – A - All prisoners are guilty. – I - Some apples are oranges – E - No apples are oranges. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 82
  • 83. Laws of Contrariety • Rule: – If A is true, E is false. – If A is false, E is doubtful. – If E is true, A is false. – If E is false, A is doubtful. – A - All cats are animals. True – E - No cats are animals. False – E - No cats are dogs. True – A - All cats are dogs. False – A - All flowers are roses. False – E - No flowers are roses. False – E - No Catholic priests are ordained. False – A - All Catholic priests are ordained. True 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 83
  • 84. Laws of Subcontrariety • Rule: – If I is false, O is true. – If I is true, O is doubtful. – If O is false, I is true. – If O is true, I is doubtful. – I - Some triangles are squares. False – O - Some triangles are not squares. True – O- Some students are not present. False – I - Some students are present. True – I - Some basketball players are tall. True – O - Some basketball players are not tall. True – O - Some scholars are not dumb. True – I - Some scholars are dumb. False 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 84
  • 85. Laws of Subalternation • Rule 1: – If A is true, I is true. – If E is true, O is true. – If A is false, I is doubtful. – If E is false, O is doubtful. – A - All surgeons are doctors. True – I - Some surgeons are doctors. True – E - No beauty titlist is ugly. True – O - Some beauty titlists are not ugly. True – A - All students are scholars. False – I - Some students are scholars. True – E - No dogs are animals. False – O- Some dogs are not animals. False 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 85
  • 86. Laws of Subalternation • Rule 2: – If I is false, A is false. – If O is false, E is false. – If I is true, A is doubtful. – If O is true, E is doubtful. – I - Some devils are good. False – A - All devils are good. False – O - Some angels are not spiritual. False – E - No angels are spiritual. False – I - Some oranges are fruits. True – A - All oranges are fruits. True – O - Some athletes are not swimmers. True – E - No athletes are swimmers. False 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 86
  • 87. Chart – Opposition of Proposition A E I O A True T F T F E True F T F T I True D F T D O True F D D T A False F D D T E False D F T D I False F T F T O False T F T F 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 87
  • 88. Activity • Topic – Square of Opposition • Instruction – Determine whether the following inferences are correct or incorrect – From the truth or falsity of the given statement, determine the symbol, judgment and relationship of the following statements – Indicate “The same proposition” if the relationship came from the same symbol and the same judgment – Encircle the symbol and judgment and write the relationship • Precision – Correct – Incorrect • Symbol – A – I – E – O • Judgment – True – False – Doubtful • Relationship – Contradiction – Contrariety – Subcontrariety – Subalternation 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 88
  • 89. Eduction • Conversion – Switch S and P Symbol Statement Converse Truth Value E No S are P No P are S Same I Some S are P Some P are S A All S are P All P are S Undetermined O Some S are not P Some P are not S 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 89
  • 90. Eduction • Obversion – Change the Quality – Negate P Symbol Statement Obverse Truth Value A All S are P No S are non P Same E No S are P All S are non P I Some S are P Some S are non P O Some S are not P Some S are not non P 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 90
  • 91. Eduction • Contraposition – Switch and Negate S and P Symbol Statement Contrapositive Truth Value A All S are P All non P are non S Same O Some S are not P Some non P are not non S E No S are P No non P are non S Undetermined I Some S are P Some non P are non S 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 91
  • 92. Eduction • Inversion 1 – Change the Quantity from Universal to Particular – Particular Quantity cannot be inversed – Change the Quality of Subject and Predicate Symbol Statement Inverse Truth Value A Every S is P Some non S is non P Same E Every S is not P Some non S is P I Cannot be inversed O 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 92
  • 93. Eduction • Inversion 2 – Change the Quantity from Universal to Particular – Particular Quantity cannot be inversed – Change the Quality of Subject and Predicate Symbol Statement Inverse Truth Value A Every S is P Some non S is non P Same E Every S is not P Some non S is not non P I Cannot be inversed O 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 93
  • 94. Activity • Topic – Eduction I • Instruction – 1. Identify the correct Eduction of the following proposition – 2. Write the letter of your choice on the space provided 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 94
  • 95. Activity • Topic – Eduction II • Instruction – State the correct Eduction of the following proposition – Double Negation does not apply – Simplifying “Not all” to “Some” does not apply 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 95
  • 96. Argument • Group of Proposition in which the Premises result in Conclusion. • Premise 1 – Anything that moves is moved by another; • Premise 2 – But, the ball moves; • Conclusion – Ergo, the ball is moved by another. 02/10/17 03:00 AM 96 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 97. Structure of Argument • Premise 1 – Anything that moves is moved by another; • Given Proposition • Premise 2 – But, the ball moves; • reason of the conclusion • serves as the evidence • Conclusion – Ergo, the ball is moved by another. • Offshoot • Claim being made • followed the evidence 02/10/17 03:00 AM 97 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 98. Not arguments • Raisins are dried grapes. Prunes are dried plums. • These are some of the symptoms of neurosis: strong guilt feeling, irrational fears, insomnia, and inability to make decisions. • It is sunny today. It is also the beginning of the week. 02/10/17 03:00 AM 98 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 99. Good Argument • Conclusion is a result of Premise • Premise – It had rained yesterday, • Conclusion – Some places have been flooded. 02/10/17 03:00 AM 99 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 100. Bad Argument • Conclusion is not a result of Premise • Premise – Identical twins who inherit the same genes have different intelligence quotient. • Conclusion – Environment must have played a role in determining intelligence. 02/10/17 03:00 AM 100 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 101. Premise Indicators • since • because • for • as • follows from • as shown by • In as much as • as indicated by • the reason is that • may be inferred from • may be derived from • may be deduced from • in view of the fact that • in that • seeing that • given that • may be concluded from • on the reason that • due to the fact that • based on the premise that 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 101
  • 102. Conclusion Indicators • therefore • hence • thus • so • wherefore, • accordingly, • in consequence • consequently • proves that • as a result • for this reason • it follows that • we may infer • I conclude that • which shows that • which means that • which entails that • which implies that • which allows us to infer • which points to the conclusion that • it must be that 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 102
  • 103. Activity • Topic – Premise and Conclusion • Instruction – 1. Identify the premise and the conclusion in the following propositions – 2. Indicate the indicator of the respective premise and/ or conclusion – 3. Underline the Premise and Conclusion – 4. Write P above the Premise and C above the Conclusion – 5. Encircle the Indicator 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 103
  • 104. Premise precedes Conclusion e. g. • Premise – The investigation of supernatural phenomena lies outside the realm of science. • Conclusion – Ergo, science can neither prove nor disprove the existence of God. 02/10/17 03:00 AM 104 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 105. Premise precedes Conclusion e. g. • Premise – Because many are rightly concerned about the troublesome state of affairs that currently exists between Christian and Moslem in Egypt. • Conclusion – It is understandable to look to the legal system for help in addressing the problem. 02/10/17 03:00 AM 105 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 106. Premise precedes Conclusion e. g. • Premise – Wisdom is the principal thing; • Conclusion – Ergo, seek the pursuit of wisdom. 02/10/17 03:00 AM 106 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 107. Premise precedes Conclusion • shows that • indicates that • proves that • entails that • implies that • establishes that • Activity – Make propositions using these indicators. 02/10/17 03:00 AM 107 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 108. Conclusion precedes Premise e. g. • Conclusion – The Food and Drug Administration should stop all cigarette sales immediately. • Premise – After all, cigarette smoking is the leading preventable cause of death. 02/10/17 03:00 AM 108 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 109. Conclusion precedes Premise e. g. • Conclusion – Moreover, cutting SSS will not improve the deficit problem. As the Secretary of Department of Budget has noted, • Premise – Social security is funded by separate payroll taxes and contributes not a peso to the deficit. 02/10/17 03:00 AM 109 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 110. Conclusion precedes Premise • Activity – Make propositions using these indicators. • is shown by • is indicated by • is proven by • is entailed by • is implied by • is established by 02/10/17 03:00 AM 110 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 111. Activity • Topic – Premise precedes Conclusion and Conclusion precedes premise • Instruction – 1. Write N if it is not an argument. – 2. If it is an argument, write PC if the Premise precedes Conclusion. – 3. Write CP if the Conclusion precedes Premise 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 111
  • 112. Statement to Argument • The president, being human, is mortal, as all human beings are mortal. • Premise 1 – All human beings are mortals. • Premise 2 – The president is a human being. • Conclusion – Ergo, the president is mortal. 02/10/17 03:00 AM 112 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 113. Statement to Argument • God does not exist because if he did there would be no suffering and evil in the world; but obviously suffering and evil do exist. Thus, there is no God. • Premise 1 – If God existed there would be no suffering and evil in the world. • Premise 2 – But obviously suffering and evil do exist. • Conclusion – Ergo, there is no God. 02/10/17 03:00 AM 113 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 114. Statement to Argument • All mammals feed their young with milk. All humans are mammals. Ergo, all humans feed their young with milk. • Activity – Transform the statement into an argument. 02/10/17 03:00 AM 114 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 115. Statement to Argument • All that feed their young with milk are mammals. All humans feed their young with milk. Ergo, all humans are mammals. • Activity – Transform the statement into an argument. 02/10/17 03:00 AM 115 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 116. Reasoning • Reasoning – Mental operation in which propositions are compared into order to create a meaningful conclusion. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 116
  • 117. Validity of Reasoning • Rules: – The conclusion should flow from the material content of the premise – An argument containing true premises cannot have a false conclusion • Valid E.g. – All sharks are ferocious animals. – However, some sea creatures are sharks. – Ergo, some sea creatures are ferocious animals. • Invalid E.g. – All stars are heavenly bodies. – However, Angelina Jolie is a star. – Ergo, Angelina Jolie is a heavenly body. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 117
  • 118. Activity • Topic – Validity of Reasoning • Instruction – Identify whether the argument is Valid or Invalid 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 118
  • 119. Types of Reasoning • Deduction – From General to Specific – Determines whether the argument is Valid of Invalid – Core of Aristotelian Logic – E.g. • All businessmen are millionaires • However, some businessmen are Filipinos • Ergo, some Filipinos are millionaires. • Induction – From Specific to General – Philosophy of Francis Bacon and John Stuart Mill – Determines whether the argument is correct or incorrect. – E.g. • Juan is a Filipino • Juan is a hardworking man. • Ergo, probably all hardworking men are Filipinos. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 119
  • 120. Kinds of Reasoning • Deductive – Conclusion follows necessarily from premise. – Premise supports conclusion because it is true. – Because it is impossible for the conclusion to be false. • Inductive – Conclusion follows probably from premise. – Premise supports conclusion because of it is assumedly true. – Because it is probable for the conclusion to be true. 02/10/17 03:00 AM 120 Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr.
  • 121. Deductive • Indicators – Necessarily – Certainly – Absolutely – Definitely • E.g. – If a substance is a noble gas, it is inert. Therefore, since argon is a noble gas, it necessarily follows that it is inert. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 121
  • 122. Inductive • Indicators – Probable – Improbable – Plausible – Implausible – Likely – Unlikely • E.g. – Neon has unstable isotopes. Therefore, since argon is similar in many ways to neon, it probably follows that argon has unstable isotopes, too. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 122
  • 123. Deductive vs. Inductive • Deductive – Premise 1 • All saleswomen are extroverts. – Premise 2 • Judy Wage is a saleswoman. – Conclusion • Therefore, she is extrovert. • Inductive – Premise 1 • The vast majority of saleswomen are extroverts. – Premise 2 • Rose Liam is a saleswoman. – Conclusion • Therefore, she is extrovert. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 123
  • 124. Deductive and Inductive • Arguments with no indicator – Depends on the Matter 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 124
  • 125. Forms of Deductive Reasoning • Argument based on mathematics – An argument in which the conclusion depends on some purely arithmetic or geometric computation or measurement. • E.g. – A shopper may place two apples and three oranges into a paper bag and then conclude that the bag contains five fruits. – A surveyor might measure a square piece of land and, after determining that it is 100 feet on each side, conclude that it contains 10,000 square feet. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 125
  • 126. Forms of Deductive Reasoning • Argument from definition – An argument in which the conclusion is claimed to depend upon the definition of some word or phrase used in the premise or the conclusion • E.g. – Claudia is mendacious, so she tells lies. – This paragraph is prolix, so it follows that it is excessively wordy. • Dictionary: – Mendacious • Liar – Prolix • Prolonged 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 126
  • 127. Forms of Deductive Reasoning • Categorical syllogism – A syllogism in which each statement begins with one of these quantifiers: • All • No • E.g. – Premise 1 • All lasers are optical devices. – Premise 2 • Some lasers are surgical instruments. – Conclusion • Therefore, some optical devices are surgical instruments. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 127
  • 128. Forms of Deductive Reasoning • Conditional syllogism – A syllogism having a conditional statement for one or both of its premises. • E.g. – Premise 1 • If quartz scratches glass, then quartz is harder than glass. – Premise 2 • Quartz scratches glass. – Conclusion • Therefore, quartz is harder than glass. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 128
  • 129. Forms of Deductive Reasoning • Disjunctive syllogism – A syllogism having a disjunctive statement (“either...or”) for one or both of its premises. • E.g. – Premise 1 • Either breach of contract is a crime or it is not punishable by the state. – Premise 2 • Breach of contract is not a crime. – Conclusion • Therefore, it is not punishable by the state. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 129
  • 130. Forms of Inductive Reasoning • Prediction – The premises deal with some known event in the present or past, and the conclusion moves beyond this event to some event in the relative future. • E.g. – Because certain meteorological phenomena have been observed to develop over a certain region in the Pacific, a storm will occur there in the next several hours. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 130
  • 131. Forms of Inductive Reasoning • Argument from analogy – An argument that depends on the analogy between two things. • E.g. – From knowledge that his Mercedes car is an expensive car, I argue that your car, being a Mercedes, is also expensive. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 131
  • 132. Forms of Inductive Reasoning • Inductive generalization – An argument that proceeds from the knowledge of a selected sample to some claim about the whole group. Because the members of the sample have a certain characteristic, it is argued that all the members of the group have the same characteristic. • E.g. – One may argue that because three oranges selected from a certain crate were especially tasty and juicy, all the oranges from that crate are especially tasty and juicy. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 132
  • 133. Forms of Inductive Reasoning • Argument from authority – An argument in which the conclusion rests upon a statement made by some presumed authority or witness. • E.g. – A lawyer may argue that the suspect committed no murder because an eyewitness testified to that effect under oath. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 133
  • 134. Forms of Inductive Reasoning • Argument based on signs – An argument that proceeds from the knowledge of a certain sign. • E.g. – When driving on an unfamiliar highway, one might see a sign indicating that the road makes several sharp turns one mile ahead. Based on this information, one might argue that the road does indeed make several sharp turns one mile ahead. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 134
  • 135. Forms of Inductive Reasoning • Causal inference – An argument that proceeds from the knowledge of a cause to knowledge of the effect – An argument that proceeds from the knowledge of an effect to knowledge of a cause. • E.g. Cause to effect – From the knowledge that a bottle of wine had been accidentally left in the freezer overnight, someone might conclude that it had frozen. • E.g. Effect to Cause – after tasting a piece of chicken and finding it dry and crunchy, one might conclude that it had been overcooked. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 135
  • 136. Activity • Topic – Kinds of Reasoning • Instruction – 1. Identify whether the argument is Deductive or Inductive – 2. Indicate the form of the respective argument – 3. Write the answer on the blank provided in each sentence. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 136
  • 137. Syllogism • Syllogism – Deductive Argument – Composed of three proposition • Major Premise – Consist of Predicate Term of the Conclusion and a Middle Term – Usually begin with Universal quantifier • Minor Premise – Consist of Subject Term of the Conclusion and a middle term • Conclusion – Composed of: » Predicate of the Major premise » Subject of the Minor Premise 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 137
  • 138. Perfect Syllogism • Categorical – Simple – Compound • Hypothetical – Conditional – Conjunctive – Disjunctive 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 138
  • 139. Components of Syllogism • Major Premise – All men are mortal. (M) (T) • Minor Premise – All Filipinos are men. (t) (M) • Conclusion – Ergo, all Filipinos are (t) mortal. (T) • Major Term (T) – Predicate of the Conclusion – Occurrence: Conclusion and One of the Premise • Minor Term (t) – Subject of the Conclusion – Occurrence: Conclusion and in the Premise where the Major Term does not occur • Middle Term (M) – Unites the Major and Minor Term – Does not occur in the Conclusion – Occurrence: Major and Minor Premise 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 139
  • 140. Steps in Categorical Syllogism • Major Premise – All men are mortal. (M) (T) • Minor Premise – All Filipinos are men. (t) (M) • Conclusion – Ergo, all Filipinos are (t) mortal. (T) • 1. Look for Conclusion • 2. Predicate in Conclusion – Major Term (T) • 3. Subject in Conclusion – Minor Term (t) • 4. Premise with the Major Term (T) – Major Premise • 5. Premise with the Minor Term (t) – Minor Premise • 6. Common Term in the Major Premise and Minor Premise – Middle Term (M) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 140
  • 141. Activity • Topic – Categorical Syllogism Steps • Instruction – 1. Identify the Major Premise, Minor Premise and Conclusion. – 2. Underline and identify the Major Term (T), Minor Term (t) and Middle Term (M) using the proper symbols following the Steps in Categorical Syllogism. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 141
  • 142. Rules of Categorical Syllogism • Rule No. 1 – There must be only three categorical proposition • All golds are metals. • All jewelries are golds. • Ergo, all jewelries are metals. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 142
  • 143. Rules of Categorical Syllogism • Rule No. 2 – There must be only three univocal terms, each of which occurs twice but not in the same proposition • All flowers are beautiful. (M) (T) • Tulip is a flower. (t) (M) • Tulip is beautiful. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 143
  • 144. Rules of Categorical Syllogism • Rule No. 3 – The middle term must be distributed (Universal) at least once • All trees are plants. (M) (T) • All Bonsai are trees. (t) (M) • Ergo, all Bonsai are plants. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 144
  • 145. Rules of Categorical Syllogism • Rule No. 4 – If the term is distributed (Universal) in the conclusion, then such term must be distributed (Universal) in a premise • Major and Minor terms must not be universal in the conclusion if they are not universal in the premises. • Some metals are cars. (M) (T) • All robots are metals. (t) (M) • Ergo, all robots are cars. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 145
  • 146. Rules of Categorical Syllogism • Rule No. 5 – There must be no two particular premises; one premise must be universal • Some metals are gold. (M) (T) • All rings are metals. (t) (M) • Ergo, all rings are gold. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 146
  • 147. Rules of Categorical Syllogism • Rule No. 6 – If one premise is particular, the conclusion must be particular • Some stones are pearl. (M) (T) • All crowns are stones. (t) (M) • Ergo, some crowns are pearl. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 147
  • 148. Rules of Categorical Syllogism • Rule No. 7 – If the conclusion is negative, only one premise must be negative • All stars are cute. (T) (M) • Some comedians are not cute. (t) (M) • Ergo, some comedians are not stars. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 148
  • 149. Rules of Categorical Syllogism • Rule No. 8 – If the conclusion is affirmative then both premises must be affirmative • All legislators are senators. (t) (M) • All senators are honest. (M) (T) • Ergo, all legislators are honest. (t) (T) 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 149
  • 150. Activity • Topic – Categorical Syllogism Rules • Instruction – 1. Identify the Rule Violated in the following Categorical Syllogism – 2. Write the rule statement beside the given Syllogism. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 150
  • 151. Figures of Categorical Syllogism 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 151 Figure 1 Figure 2 M P S M S P P M S M S P Figure 3 Figure 4 M P M S S P P M M S S P
  • 152. Moods of Categorical Syllogism • Valid Moods of Figure 1 – AAA Barbara – AII Darii – EAE Celarent – EIO Ferio • Valid Moods of Figure 2 – AOO Baroco – AEE Camestres – EAE Cesare – EIO Festino 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 152
  • 153. Moods of Categorical Syllogism • Valid Moods of Figure 3 – AAI Darapti – AII Datisi – EAO Felapton – EIO Ferison – IAI Disamis – OAO Bocardo • Valid Moods of Figure 4 – AAI Bramantip – AEE Camenes – EAO Fesapo – EIO Fresison – IAI Dimaris 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 153
  • 154. Activity • Topic – Categorical Syllogism - Figures and Moods • Instruction – 1. Determine the Figures and Moods of the following Categorical Syllogism – 2. Write your answer of the space provided 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 154
  • 155. Hypothetical Syllogism • Hypothetical Syllogism – Contains major premise that is hypothetical proposition – Forms: • Conditional Syllogism • Conjunctive Syllogism • Disjunctive Syllogism • E.g. – If penguins are birds then they have feathers and wings. – However, penguins are birds. – Ergo, they have feathers and wings. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 155
  • 156. Conditional Syllogism • Conditional Syllogism – Have conditional major premise – Indicators: • If then – Modus Ponens • Posit the antecedent and the consequent – Structure • S P • S • P • E.g. Valid – If you are beautiful then you have many admirers. – However, you are beautiful – Ergo, you have many admirers. • E.g. Invalid – If you are beautiful then you have many admirers. – However, you have many admirers. – Ergo, you are beautiful. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 156
  • 157. Conditional Syllogism • Conditional Syllogism – Have conditional major premise – Indicators: • If then – Modus Tollens • Sublate the consequent and antecedent – Structure • S P • P • S • E.g. Valid – If you are an athlete then you are energetic. – However, you are not energetic. – Ergo, you are not an athlete. • E.g. Invalid – If you are an athlete then you are energetic. – However, you are not an athlete. – Ergo, you are not energetic. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 157
  • 158. Activity • Topic – Conditional Syllogism • Instruction – Identify whether the argument is a valid Modus Ponens or Modus Tollens 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 158
  • 159. Conjunctive Syllogism • Conjunctive Syllogism – Indicator: • And – Ponendo-Tollens • Posit one term of the major premise in the minor premise • Sublate one term of the major premise in the conclusion – Structure • Positive Minor Premise • Negative Conclusion • E.g. Valid – You cannot be a manager and a janitor at the same time – However, you are a manager. – Ergo, you are not a janitor. • E.g. Invalid – You cannot be a manager and a janitor at the same time – However, you are not a manager. – Ergo, you are a janitor. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 159
  • 160. Activity • Topic – Conjunctive Syllogism • Instruction – Identify whether the argument is Valid or Invalid 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 160
  • 161. Disjunctive Syllogism • Disjunctive Syllogism – Indicators: • Either or – Ponendo-Tollens • Minor premise posits a member of major premise • Conclusion must Sublate the other remaining member – Structure • Major Premise cannot be both true in Minor Premise and Conclusion • Positive Minor premise • Negative Conclusion • E.g. Valid – Man is either biped or quadruped. – However, man is biped. – Ergo, man is not quadruped. • E.g. Invalid – Man is either biped or quadruped. – However, man is biped. – Ergo, man is quadruped. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 161
  • 162. Activity • Topic – Disjunctive Syllogism • Instruction – Identify whether the argument is Valid or Invalid 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 162
  • 163. Imperfect Syllogism • Polysyllogism – Enthymeme • First Order • Second Order • Third Order – Sorites • Aristotelian • Goclenian – Dilemma • Simple • Complex – Epichireme • Explained with: – Because – Since – Insofar – In as much02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 163
  • 164. Enthymeme • First Order – Major Premise is omitted • Second Order – Minor Premise is omitted • Third Order – Conclusion is omitted • E.g. – Given: • Every artist is imaginative. • However, Picasso is an artist. • Ergo, he is imaginative. – First Order • Picasso is an artist. • Ergo, he is imaginative. – Second Order • Every artist is imaginative. • Ergo, Picasso is imaginative. – Third Order • Every artist is imaginative. • Picasso is an artist. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 164
  • 165. Activity • Topic – Enthymeme • Instruction – Fill the three orders of Enthymeme 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 165
  • 166. Sorites • Aristotelian Sorites – Predicate of the Premise is the Subject of the Series of Conclusion excluding Final Conclusion – Final Conclusion is composed of: • Subject of the First Premise • Predicate of the Last Conclusion • Goclenian Sorites – Reverse of Aristotelian Sorites – Subject of the Premise is the Predicate of the Series of Conclusion excluding Final Conclusion – Final Conclusion is composed of: • Subject of the Last Conclusion • Predicate of the First Premise • E.g. Aristotelian Sorites – Philippines is an archipelago. – An archipelago is a land surrounded by water. – A land surrounded by water is an island. – An island is a mass of land. – A mass of land is not an ocean. – Ergo, Philippines is not an ocean. • E.g. Goclenian Sorites – A mass of land is not an ocean. – An island is a mass of land. – A land surrounded by water is an island. – An archipelago is a land surrounded by water. – Philippines is an archipelago. – Ergo, Philippines is not an ocean. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 166
  • 167. Activity • Topic – Sorites • Instruction – Identify whether the syllogism is Aristotelian Sorites or Goclenian Sorites 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 167
  • 168. Fallacy Illicit Process • Fallacy Illicit Process – Violates the rules of distribution – Term appears to be Universal or Particular in the Conclusion, but not in the Premise – Positive Proposition makes Particular Predicate – Negative Proposition makes Universal Predicate • Fallacy Illicit Major • Fallacy Illicit Minor • Fallacy of Undistributed/ Particular Middle 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 168
  • 169. Fallacy Illicit Major • Fallacy Illicit Major – Violates the rules of distribution – Major Term appears to be Universal or Particular in the Conclusion, but not in the Major Premise – Positive Proposition makes Particular Predicate – Negative Proposition makes Universal Predicate • E.g. – All dogs are mammals. • Middle Universal + Major Particular – No cats are dogs. • Minor Universal - Middle Universal – Ergo, no cats are mammals. • Minor Universal - Major Universal 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 169
  • 170. Fallacy Illicit Minor • Fallacy Illicit Minor – Violates the rules of distribution – Minor Term appears to be Universal or Particular in the Conclusion, but not in the Minor Premise – Positive Proposition makes Particular Predicate – Negative Proposition makes Universal Predicate • E.g. – All cats are felines. • Middle Universal + Major Particular – All cats are mammals. • Middle Universal + Minor Particular – Ergo, all mammals are felines. • Minor Universal + Major Particular 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 170
  • 171. Fallacy of Undistributed Middle • Fallacy of Undistributed/ Particular Middle – Violates the rules of distribution – Only one Middle Term must be Particular – Positive Proposition makes Particular Predicate – Negative Proposition makes Universal Predicate • E.g. – All mammals are animals. • Major Universal + Middle Particular – Some animals are brute. • Middle Particular + Minor Particular – Ergo, not all brute are mammals. • Minor Particular - Major Universal 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 171
  • 172. Debate • Structure of Debate – Constructive Speech • Affirmative first contender – Interpellation – Question » Destroy – Answer » Defend 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 172
  • 173. Debate• Types of Debate – Lincoln-Douglas/ Two men debate • 1 Affirmative and 1 Negative – Rebuttal • 3 Members per side • All members can rebut the speaking opponent except the 1st affirmative who will close the debate – Parliamentary/ Oregon-Oxford • 3 Speakers • 1st speaker affirmative starts the debate and be interprellated by the 1st Speaker negative. • 1st speaker negative starts and be interprellated by 2nd speaker affirmative and so on. • 1st speaker affirmative will interprellate the last negative speaker and will close the debate. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 173
  • 174. Debate– Valid Objections • Objection Your Honor/ Mr. Moderator, the question is: – Irrelevant/ Misleading/ Beyond the scope of the topic » Question is nothing to do with the topic » Purposely throwing off track the topic – Vague and Kilometric » Question could not be understood – Immaterial/ Has no basis/ Hearsay » Doubtful evidence – Hypothetical » Based on assumptions – Calling for Opinion » Speculation » Personal » Beyond expertise – Calling for two extremes » Misleading choices – Argumentative » Cannot be proven – Badgering » Shouting » No room for answer – Leading » Complex Question – Repulsive to the Senses » Pictures of dead, garbage, etc. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 174
  • 175. Debate – Qualifications • Your Honor/ Mr. Moderator – May I qualify my answer? The question is complex. – Questions • Structured – Series of deductions • Single – Seeking evidence that opponent does not have • Straw – Rapid Fire » Rattles and Pressure the other side • Rebuttal Speech • Team Captain of both sides – Fallacies • Accidents • False Cause • Consequent • Complex Question • Begging the Question • Absolute • Ad Hominem • Ad Populum • Misericordiam • Ad Verecundiam • Ad Baculum • Ad Ignorantiam • Non-sequitor 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 175
  • 176. Topics for Debate • Should abortion be legal? • Should death penalty be allowed? • Should prostitution be legal? • Should euthanasia be allowed? • Should gay marriage be legal? • Should divorce be legal? • Should marijuana be legal? • Should sex education be allowed? • Is animal testing justified? • Should polygamy be legal? • Is social networking good for society? • Is age important factor in relationship? • Is male superior to female? • Is money more important than love in marriage? • Should housewives be allowed to be bread winner? • Should homework be banned? • Should Priest be allowed to marry? • Should Seminarians be allowed to have girlfriends? • Does God exist? 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 176
  • 177. Fallacy • Fallacy – In English term • Error • Prejudice • Mistaken Impression • Illusion • Fallacy – In Logical term • Fallere (Latin) to deceive • Error of reasoning • Inadequate evidence for the conclusion. • False argument that has the appearance of truth • Paralogism or ignorance • Mistake in reasoning – Mistake in judgment 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 177
  • 178. Sophism • Sophism – Sophistry – Fallacy committed with the intention to deceive or mislead an opponent 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 178
  • 179. Formal Fallacies • Fallacies of Ambiguity – Fallacies of clearness – Contain ambiguous words or phrases – Confusion in the meaning of words • Logical Fallacies 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 179
  • 180. Dichotomy • “Either . . . Or” statement is used • The alternatives are falsely presented exhaustively • Eliminating the undesirable alternative, leaving the desirable alternative • E.g. – Either you let me have a grand debut party or I will be miserable for the rest of my life. I know you do not want me to be miserable for the rest of my life, so it follows that you will have me a grand debut party. – Either you will cheat or fail in the examination. Surely you do not want to fail the examination. Therefore, you will cheat. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 180
  • 181. Equivocation • The same word or phrase is used with two or more meanings • E.g. – A law can be repealed by legislative authority. The law of gravity is a law. Therefore, the law of gravity can be repealed by the legislative authority. – No designing persons are to be trusted; But, architects are people who make designs; Therefore, architects are not to be trusted. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 181
  • 182. Amphiboly • The grammatical construction of a sentence is not clear and is therefore open to different interpretation • E.g. – John told Bob that he had made a mistake. It follows that John has at least the courage to admit his own mistakes – My mother told your mother that she should go to the SSS office – The dog of a lady with long tail is lost 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 182
  • 183. Composition • What is true of the parts of a whole is also true of the whole thing • Taking collectively what should be taken individually • The whole is this because the parts are these • E.g. – A feather is light. Therefore, a plastic containing a billion feathers is light. – Each member of the orchestra is excellent, so the orchestra is excellent. – Each player on this basketball team is an excellent athlete. Therefore, the team as a whole is excellent. – Every atom in my body is invisible. Therefore, I am invisible. – Each brick in this building is rectangular in shape. Ergo, this building must be rectangular in shape. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 183
  • 184. Division • What is true of the whole is also true of the parts of the whole thing • Taking individually what should be taken collectively • The parts are these because the whole is this • E.g. – Salt is a nonpoisonous compound. Therefore, its component elements, sodium and chlorine, are non- poisonous. – The senate passed the RH Law. Ergo, every member of the senate is in favor to it. – Humans are the only animals capable of philosophical thinking. Thus, every person is capable of philosophical thinking. – Since a nation is powerful, every individual citizen of that nation is powerful.02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 184
  • 185. Accent • Arises from the mistaken interpretation of a statement but the mistake is due to the ambiguity in the way the statement is spoken • The arguer illegitimately stresses one or more words in the given statement and then proceeds to draw a conclusion based on the resultant interpretation • E.g. – Woman without her man is useless. – Recycle clothes and waste paper. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 185
  • 186. Prosody • Contains a word that is: – Misleading – Confusing • E.g. – Thou shall not covet thy neighbor's wife. However, Mr. Santos is not my neighbor. Ergo, I can covet his wife. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 186
  • 187. Figure of Speech • Argues from the construction of one word to the form and the construction of another • E.g. – Insecure is contradictory of secure. Insincere is also the contradictory of sincere. Ergo, inflammable is the contradictory of flammable. – Anybody restless is not restful. Anybody careless is not careful. Ergo, anybody helpless is not helpful. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 187
  • 188. Informal Fallacies • Fallacies of Relevance – Overlooks the fact – No connection between the premises and the conclusion – Argument relies on premises that are not relevant to its conclusion and ergo cannot establish its truth • Material Fallacies 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 188
  • 189. Argumentum ad baculum • Appeal to force – Use of threat • physical or psychological – Physical force or moral pressure rather than the merit of the point at issue – Discourse of power – Pointing out their powers over you – Warning you of the bad consequences of refusing to accept their argument • E.g. – Thus there is ample proof of the truth of the Bible. All those who refuse to accept that truth will burn in Hell. – Ladies and gentlemen of the jury, if you do not bring in a verdict of guilty, you may be this killer’s next victim! 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 189
  • 190. Argumentum ad baculum • Appeal to force – Use of threat • physical or psychological – Physical force or moral pressure rather than the merit of the point at issue – Discourse of power – Pointing out their powers over you – Warning you of the bad consequences of refusing to accept their argument • E.g. – Be home by nine tonight or you can forget about the increase in allowance next week. – You better agree to my proposal or you won't see your family anymore. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 190
  • 191. Argumentum ad baculum • Appeal to force – Use of threat • physical or psychological – Physical force or moral pressure rather than the merit of the point at issue. – Discourse of power – Pointing out their powers over you – Warning you of the bad consequences of refusing to accept their argument. • E.g. – You have just heard the new policies in our company. They are effective immediately. Anyone who disagrees may now resign. The portal of the company is open. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 191
  • 192. Argumentum pansarilum • Argument to one’s own advantage – Offer would be heed unless advantage will be given regardless of morality • E.g. – I will pay for your mother’s hospital bill provided that we will sleep together tonight 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 192
  • 193. Argumentum ad misericondiam • Appeal to pity – Causes sympathy – Pleading for mercy and disregarding the point in argument – Pity or sympathy must be irrelevant to the issue • Relevant – Hungry beggar who begs for food – A man who on bended knees appeals to a criminal to spare his life • E.g. – We cannot condemn this man because he is the only one that supports his family. – I did not murder my mother and father with an axe! Please don't find me guilty; I'm suffering enough through being an orphan. – Imelda Marcos cries over jury on Yamashita trial. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 193
  • 194. Argumentum ad misericondiam • Appeal to pity – Causes sympathy – pleading for mercy and disregarding the point in argument – Pity or sympathy must be irrelevant to the issue • Relevant – Hungry beggar who begs for food – A man who on bended knees appeals to a criminal to spare his life • E.g. – A student should be given a passing grade because he is soon to graduate, or because if he fails the course his parents would disown him. – Vote for this candidate because he has already put in a lot of money and heartache in the campaign. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 194
  • 195. Argumentum ad misericondiam • Appeal to pity – Causes sympathy – Pleading for mercy and disregarding the point in argument. – Pity or sympathy must be irrelevant to the issue • Relevant – Hungry beggar who begs for food – A man who on bended knees appeals to a criminal to spare his life • E.g. – I hope you could add more compassion in your heart by letting me pass in this bar examination. Anyway, I am already old. To retire as a full-pledge lawyer is all I dream of. – Please accept me to work in your company. I have 5 children to feed and my wife is bed ridden. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 195
  • 196. Argumentum ad crumenam • Believing that money is a criterion of correctness • Those with more money are more likely to be right • E.g. – Microsoft software is undoubtedly superior; why else would Bill Gates have gotten so rich? – Apple must be the best manufacturer of quality gadgets, why else would it be so expensive? – Give me a passing mark Sir, and we will talk about the payment. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 196
  • 197. Argumentum ad lazarum • Lazarus – Jesus raised from being dead • Assuming that someone poor is sounder or more virtuous than someone who's wealthier • E.g. – Priests are more likely to possess insight into the meaning of life, as they have given up the distractions of wealth. – Tenants of Hacienda Luisita should be given a parcel of land from the vast land of Cojuanco because they have work hard on it. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 197
  • 198. Argumentum ad populum • Appeal to the people or appeal to emotion – Enthusiasm and emotional support – Attempts to win popular assent using emotive language – Mobilizing public sentiment – Direct or Indirect • E.g. – Legalize cockfighting because many people are engaging in it anyway. – The constitution is defective because many people want it to be amended. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 198
  • 199. Argumentum ad populum • Direct – Excite the emotion and enthusiasm of the crowd – Arouse a kind of mob mentality – Employs emotional charge phraseology • E.g. – Political campaigns • Iboto si Jingoy Estrada, Anak ng Ama ng masa, Anak ng bawat masa. – Slogans – Labels 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 199
  • 200. Argumentum ad populum • Indirect – Appeal is addressed to one or more individuals separately • E.g. – Bandwagon • 9 out of 10 Moms trust Lactum. You will be left behind if you do not use the product. – Vanity • “Only Belo touches my skin.” – Kris Aquino – Snobbery • An apple gadget is not for everyone. If you think you belong to the select few, this distinguished smart phone is for you! 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 200
  • 201. Argumentum ad antiquitatem • Antique – Old • Asserting that something is right or good simply because it's old • That's the way it's always been • E.g. – For thousands of years Christians have believed in Jesus Christ. Christianity must be true, to have persisted so long even in the face of persecution. – UST must be the best institution for being the oldest in Asia. – UIC must be guided by the holy spirit because it stands for a century. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 201
  • 202. Argumentum ad novitatem • Novitiate – New • Asserting that something is better or more correct simply because it is new • E.g. – The Clash of Clans is way cooler than Super Mario because it was just in market last week. – Kia vehicles are more durable than Toyota vehicles because it is the newest brand in the market. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 202
  • 203. Poisoning the well • No chance has the second man got if the first man calls him a liar before he even begins talking • E.g. – Two men are having a debate. The first one gets up and says, 'My opponent is a notorious liar. You can't believe a word that he is going to say.' 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 203
  • 204. Argumentum ad hominem • Attack against the person – Attack is not at the conclusion of an opponent but at the person of the opponent himself – Attack upon the person rather than the persons’ ideas. – What he says should not be believed because of his character flaw – Attacking the person instead of proving or disproving the point at issue • Abusive • Circumstantial • Tu quoque 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 204
  • 205. Argumentum ad hominem • Abusive – Attack is directly against a person seeking to defame or discredit him • Opponent possesses a certain undesirable or negative characteristic • Opponents’ words or abilities are not to be trusted because of that characteristic • E.g. – Well now, you have all heard Professor Clark tell us about the theory of evolution. But I am not surprised that he neglected to tell you that he is a godless atheist! How can this man speak the truth, I ask you? 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 205
  • 206. Argumentum ad hominem • Circumstantial – Opponent has self- centered interest on the topic • E.g. – The mall industry lobbyists have been arguing that tax reform is not necessary. But just remember this: it is the mall industry that stands to benefit the most if there is no change in the current tax laws. – A student of UM predicts that the basketball team of ADDU will win the championship match. A fellow student of UM might raise his eyebrows and ask him, "Where does your loyalty belong to, anyway?"02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 206
  • 207. Argumentum ad hominem • Tu quoque – Shifting the burden of guilt – One defends oneself by accusing the attacker of usually similar wrongdoing. – “Two wrongs do not make a right” so that even if the arguer is right in attacking his accuser, he has not defended himself against the charge – Character of an individual is logically irrelevant to the truth or falsehood of what the person says – May persuade by the psychological process of transference • E.g. – Yes, I admit, I cheated on you last night. But you also cheated on me before. – You say I’m not pretty? Well, you’re not pretty as well. How can you be in the position to say that? 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 207
  • 208. Argumentum ad vercundiam • Appeal to misplaced or inappropriate authority – Claimant is not authorized to discuss the subject matter – Based not on the intrinsic merits of the claim but on the prestige or fame of the person endorsing the claim – Appeal to authority with respect to matters outside his specialization • E.g. – How can that definition of love be questioned, criticized or doubted when it was Blaise Pascal, a known mathematician who gave that. – My assignment in Logic is not wrong. Miss Rowling, my English teacher who is known internationally as a novelist, confirmed my answer. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 208
  • 209. Critique on Argumentum ad vercundiam by Prof. Sam Bernales, Jr. • Defending the misplaced or inappropriate authority – Claimant may not be an expert to discuss the subject matter but the argument may be accepted based on the person’s passion on the subject matter. • E.g. – Giorgio Tsoukalos of Ancient Aliens, History Channel, discusses about the presence of Aliens in Ancient History of the World. Giorgio Tsoukalos is a graduate of Bachelor of Arts in Mass Communication major in Sports Communication. However, he still merited by the prestigious History Channel based on his enthusiasm on the subject. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 209
  • 210. Argumentum ad ignorantiam • Appeal to ignorance – Proposition is true • because it has not been proved false – Proposition is false • because it has not been proved true – Lack of evidences • E.g. – Well, I have examined all the arguments for the existence of God, and I have seen that none of them proves that God exists. That is reason enough for me: there is no God! – Angela Frank is a paragon of honesty because she never cheats. – I am sure that the students have understood the instructions perfectly well because no one raised a hand to ask anything on my lesson. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 210
  • 211. Dicto simpliciter • Accident – A general rule is applied wrongly to a specific case – From general to particular • E.g. – Jogging is good for the health. Ergo, a newly-heart-operated patient should always jog for good health. – Freedom of speech is a constitutionally guaranteed right. Therefore, that radical communist should not be arrested for his speech that incited that riot last week. – All good soldiers should obey their superiors' orders. Therefore, they should also obey the captain even if he is exceedingly in authority. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 211
  • 212. Dicto simpliciter • Accident – A general rule is applied wrongly to a specific case – From general to particular • E.g. – One has to tell the truth always. Thus, if a murderer confesses his crime to a priest, it is but proper for the priest to reveal the truth to the authority. – Customer is always right. Therefore, the cashier should return my money because I changed my mind after purchase. – A good student abides the teacher. Ergo, a beautiful student should abide the teacher who implies indecent favor. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 212
  • 213. Dicto simpliciter • Accident – A general rule is applied wrongly to a specific case – From general to particular • E.g. – Killing is immoral. Ergo, soldiers and policemen should not kill in the face of threat. – Households should obey their masters. Ergo, domestic helpers should obey their masters imposing sexual assault. – Every citizen has the right to bear arms. Ergo, Sisa, who has been declared insane, should not be disarmed. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 213
  • 214. Dicto simpliciter • Accident – Accident is given more emphasis rather than the Essence • E.g. – Mr. Estrada is not my father. My father is not a drunkard, a womanizer and a gambler. – You are not my boyfriend. I have no cheating boyfriend. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 214
  • 215. Converse accident • Hasty generalization – Conclusion is drawn out of the sample that is not a representative of the group – One moves carelessly or too quickly from a single case to a broad generalization – From particular to general • E.g. – I know that Philosophers are weird and odd people because I have seen that in my teachers behavior. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 215
  • 216. Post hoc • False Cause – The link between premises and conclusion depends on some imagined causal connection that does not exist – Superstitious beliefs or Oversimplification • E.g. – It rains whenever she arrives, ergo to avoid rains we must not invite her to come over. – During the past two months, every time that the cheerleaders wore blue ribbons in their hair, the basketball team was defeated. Therefore, to prevent defeats in the future, the cheerleaders should get rid of those blue ribbons. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 216
  • 217. Post hoc • False Cause – Superstitious beliefs • Cultural • Pass on from one generation to another • E.g. – He met an accident because it was Friday the 13th . – A black cat crossed my path and later I tripped and sprained my ankle. It must be that black cats are really bad luck. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 217
  • 218. Post hoc • False Cause – Oversimplification • An arguer explains the occurrence of some event or phenomenon in terms of one or more of its least important causes • E.g. – I blame the television media for the epidemic of hijackings, kidnappings, and other acts of terrorism. If we would stop televising terrorist acts, they would stop. – The divorce rate in America has been climbing steadily. At the same time, the number of juveniles getting into trouble with the law has shoot up. Something must be done about the divorce rate since it is causing such a rapid increase in juvenile delinquency. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 218
  • 219. Non-sequitor • It does not follow – Conclusion does not necessarily follow from our premises • E.g. – I love you therefore it follows that you love me. – She is the most beautiful student in this University ergo she should be given a scholarship. – He goes to Church everyday ergo it is impossible for him to do corruption. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 219
  • 220. Ignoratio elenchi • Ignorance of the proof – Irrelevant conclusion – Missing the point • Draws a conclusion that misses the point entirely • E.g. – Crimes of theft and robbery have been increasing at an alarming rate lately. The conclusion is obvious: we must reinstate the death penalty immediately. – The man is currently suffering from amnesia and has no recollection whatever of the event of the past two weeks. We can only conclude that he did not commit the crime of murdering his neighbor, as he has been accused of doing. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 220
  • 221. Contradictory Premise • Premises contradict each other • E.g. – If God can do anything, can He make a stone so heavy that He won't be able to lift it? But if He can do anything, He can lift the stone. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 221
  • 222. Genetic • Taking the origin as evidence • E.g. – Ferdinand Marcos Jr. was raised by his Father who declared Martial Law. It is clear that upon winning the Presidential election, Ferdinand Marcos Jr. will also declare Martial Law. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 222
  • 223. False Dilemma • 1 of the 2 claims was proven false. Therefore, the other is doubtless true. • Jejomar Binay and Mar Roxas are both running for Presidency. Jejomar Binay was accused of corruption. Therefore we should vote for Mar Roxas for President. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 223
  • 224. Petitio principii • Begging the question – Circular argument • The premise of the argument is simply a reinstatement of the conclusion • E.g. – Birds know how to fly because they have wings and wings can make them fly. – Philosophers are highly intelligent individuals because if they were not highly intelligent they would not be philosophers. – The Bible asserts that God exists. The Bible is the divine word of God. Therefore, God exists. – "Why are you here?" "Because I'm not there.“ – Declarative sentence is the sentence that declares. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 224
  • 225. Complex question • A question is asked in such a way as to presuppose the truth of some assumption buried in that question • 1 Question (Actually 2 questions) = 1 Answer • E.g. – Have you stopped cheating on your girlfriend? – Do you still cheat on exams? – Is this the knife you used to kill the victim? – Where did you hide the money you stole? – What did you use to wipe your fingerprints from the gun? 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 225
  • 226. False analogy • The analogy is not strong enough to support the conclusion that is drawn • The assumption is that if two or more things are alike in some respects, they are alike in some other respect • Analogy or resemblance is not sufficient to warrant the conclusion • E.g. – Bobby’s new car is bright blue, has leather upholstery, and is expensive. Crowley’s new car is also bright blue and has leather upholstery. Therefore, it is also expensive. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 226
  • 227. Hypothesis Contrary to Fact • Hypothesis that is not true and then draw any supportable conclusions from it • E.g. – If Madame Curie had not happened to leave a photographic plate in a drawer with a chunk of pitchblende, the world today would not know about radium. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 227
  • 228. Slippery slope • Claims that a certain event will set off a chain reaction, leading in the end to some undesirable consequence, yet there is no sufficient reason to think that the chain reaction will actually take place • E.g. – Attempts to outlaw pornography threaten basic civil rights and should be summarily abandoned. If pornography is outlawed, censorship of newspapers and news magazines is only a short step away. After that there will be censorship of textbooks, political speeches, and the content of lectures delivered by university professors. Complete mind control by the central government will be the inevitable result. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 228
  • 229. Slippery slope • Claims that a certain event will set off a chain reaction, leading in the end to some undesirable consequence, yet there is no sufficient reason to think that the chain reaction will actually take place • E.g. – Studying philosophy is a dangerous thing to do. It makes you critical., which in turn makes you skeptical of your religious beliefs. And once you have begun to lose faith in your religion, it is a small step to atheism and immorality, and a life of immorality is damned. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 229
  • 230. Red herring • The arguer diverts the attention of the reader or listener by addressing a number of extraneous issues and ends by presuming that some conclusion has been established • The fallacy got its name from the practice of using a herring, a particularly smelly fish when cooked, to divert hunting dogs from the scent of a fox • Directing attention away from the issue to other seemingly related issues • E.g. – Friends and neighbors I urge you to defeat the proposal to make jail sentences mandatory for drunk drivers. My opponent claims that it will reduce the number of accidents caused by drunk drivers. But if we really want to reduce traffic accidents, then we should stand behind those men and women whose chief responsibility is our safety. I am referring of course, to our valiant police officers, what we need to do is increase their salaries, beef up the police force, and, most importantly, stop butting into their business with troublesome people. 02/10/17 03:00 AM Critical Thinking and Correct Reasoning Prof. Sam Bernales, Jr. 230

Editor's Notes

  1. Collective: Males, Particular: 80% of Males, Singular: This Place, Universal, Table, Chair, Door, Camera