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1. Introductory Notion of Judgment
The mind does not stop in the formation of
ideas and terms.
It starts asserting relationship between
these concepts, either affirming or denying
it.
Examples:
“Juan is a Filipino”. Judgment
“Juan is not a Filipino”.

2. What is Judgment in Logic?
• A mental act of affirming or denying the
relationship between two concepts. A
mental operation or act by which the mind
affirms or denies anything whatsoever.
• Some people are generous
Affirmation
Man is a creature.
Denial A dog is not rational.
A tree is not a cow.

3. Examples of Judgment
Every man is a rational animal.
No dog is human.
A tree is not a cow.
Baguio City is the summer capital of the
Philippines.
Joseph “Erap” Estrada is the president of
the Philippines.
Some people are generous.

4. Judgment and Proposition
Theoretically, judgment is a mental act not
yet verbally expressed. It exists only in the
mind. But ideas need terms as a means of
expression, so judgments need a tool for
communication. This tool is called
PROPOSITION. Therefore, every
proposition is a judgment.

5. Prerequisites of Judgment
For a judgment to be valid and true
certain prerequisites must be followed.
They are the following:
1. The two related concepts must be
thoroughly understood.
2. There must be an intellectual
comparison between the two concepts/
terms. The mind must comprehend their
identity or non-identity as basis for
pronouncing a judgment.

6. • 3. There must be an objective perception
of the relationship of the two concepts
whether or not such relationship is of
agreement or disagreement.
• 4. There must be a mental pronouncement
of the agreement or disagreement of the
terms compared.

7. Introductory Notion of Proposition
A judgment is mental act not yet
verbally expressed. But man has the
faculty of speech and can put this in
writing. So that if ideas need terms for
expression, so judgment need a tool for
communication.
This tool is called proposition.

8. A proposition is defined as a declarative
sentence which expresses a relation of
affirmation or denial between two terms.
It is a verbal expression of judgment.

10. Types of Proposition
There are two types of proposition: the Categorical and the
Hypothetical. We shall discuss first the categorical. The Hypothetical
will be discussed later.
• CATEGORICAL PROPOSITIONS. A categorical is one in which
the predicate term is either affirmed or denied of the subject term. If
the predicate term is affirmed by the subject term the, the two terms
are united and the proposition is called affirmative. If the two terms
are denied of each other as indicated by the negative adverbs no or
not, the proposition is called negative.
The subject and the predicate are united or separated by a copula,
the present tense of the verb “to be”, am, is or are.

11. All pine trees are plants.
Some plants are not flowers.
All people are beautiful
I am a finite being.
The farmer is God’s servant.
No man is immortal.

12. Components of Categorical Proposition
1. Subject Term
2. Predicate Term
3. Copula

13. Truth or Falsity
• The mind’s act of affirming or negating a
relationship of terms in a proposition is in
fact a declaration of truth or falsity. But
how do we know a judgment is true or
false?
It is the conformity between the mental
judgment and objective reality. Or the
congruence between what is in the mind
and the objective world.

14. A tree is a plant.
The sun revolves around the earth.
Flowers are petals.
A triangle has four sides.
Igorots are Filipinos.
A dog is an irrational animal.

15. Reduction To Logical Form
• A proposition may run like this: “The dog
barks. This has to be reduced to logical
form – forming a categorical proposition by
changing the verb into a linking verb in
order to have a copula. Modify slightly or
add a word without changing the thought
of the original proposition.

16. ALL DOGS BARK. In logical form may be as
follows:
All dogs are barking animals.
All dogs are barkers.
All dogs are animals that bark.
FILIPINOS WORK HARD. In logical form may
be as follows:

17. Properties of Categorical Proposition
Quantity of Proposition
1. Universal Proposition
2. Particular Proposition
3. Singular Proposition
Quality of Proposition
1. Affirmative Proposition
2. Negative Proposition

18. Quantity and Quality Combined
• Reduction of Propositions to Four Basic
Types
UNIVERSAL / SINGULAR AFFIRMATIVE A
UNIVERSAL / SINGULAR NEGATIVE E
PARTICULAR / AFFIRMNATIVE I
PARTICULAR / NEGATIVE O

19. INFERENCE:
THE REASONING PROCESS
Nature of Reasoning
Logic is the science of correct thinking. It starts
with ideas and terms and leads to the formation of
judgment and proposition. Using judgment and
proposition it proceeds to the intellectual activity called
reasoning process or inference.

20. Notion of Inference
 the process in which from a sequence of
propositions, we arrive at a conclusion. The
mind proceeds from one proposition to other
propositions.
 Mental process of comparing 2 concepts with a
common third term in order to establish
agreement or disagreement with each other.
 Inference consists of 2 parts: the antecedent
and the consequent.

21. ANTECEDENT- CONSEQUENT RELATIONSHIP
Antecedent (premises)
S
E
Q
U
inference E
N
C
E
Consequent (conclusion)

22. Example:
Crimes are evil acts. Antecedent
But murder is a crime. Crime appears 2x.
Common 3rd term.
Sequential relation
Therefore, murder is an evil act. Consequent

23. There are three terms:
• Crimes - appears twice in the premises.
This term establishes a sequential relation
between the 2 premises.
• Evil acts
• Murder

24. Kinds of Inference
Immediate and Mediate Inference
Immediate Inference
A short-cut way of reasoning process
passing directly from one proposition, without
the aid of a second proposition or a third term, to
a new proposition but not a new truth.
example: Crimes are evil acts.
Therefore, crimes are evil acts.

25. Kinds of Inference (cont.)
Mediate Inference
A process of reasoning whereby the mind passes
from two propositions which are called premises to a new
proposition called conclusion thru the mediation of of a
common third term called the middle term. The mind
arrives at a new truth.
This reasoning process or inference is called a
syllogism.
The structure of a syllogism consists of 3 declarative
sentences: 2 premises and one conclusion.
example:
Crimes are evil acts.
But murder is a crime.
Therefore, murder is an evil act.

26. The Old Cowboy
You have lived to be 80 and know who you are...then along
Comes someone and blows it all to hell........

27. An old cowboy sat down at the Starbucks
And ordered a cup of coffee.
As he sat sipping his coffee, a young woman sat
Down next to him.
She turned to the cowboy and asked, 'Are you
A real cowboy?'

28. He replied, 'Well, I've spent my whole life breaking
Colts, working cows, going to rodeos, fixing
fences,
Pulling calves, bailing hay, doctoring calves,
cleaning
My barn, fixing flats, working on tractors, and
feeding
My dogs, so I guess I am a cowboy.'

29. She said, 'I'm a lesbian. I spend my whole day
thinking
About women. As soon as I get up in the
morning, I
Think about women. When I shower, I think
about
Women. When I watch TV, I think about women.
I even think about women when I eat. It seems
That everything makes me think of women.'

30. The two sat sipping in silence.
A little while later, a man sat down on the
other side
Of the old cowboy and asked, 'Are you a
real cowboy?'
He replied, 'Hell, I always thought I was,
but I just found
Out that I'm a lesbian'

31. TYPES OF REASONING
DEDUCTIVE REASONING
and
INDUCTIVE REASONING

32. DEDUCTIVE REASONING
- the mind proceeds from a universal
truth to a particular one.
Examples:
1. Every man is rational
But the teacher is a man.
Therefore, the teacher is rational.
2. A dog is an animal.
But a person is not an animal.
Therefore, a person is not a dog.

33. INDUCTIVE REASONING
- the mind proceeds to conclude from
individual or particular cases to the
existence of a universal law or principle.
Example:
Filipinos have 2 eyes each.
Americans have 2 eyes each.
Chinese have 2 eyes.
But Filipinos, Americans and Chinese are people.
Therefore, people have 2 eyes each.

34. THE CATEGORICAL SYLLOGISM
- a verbal expression of an inference. An oral
or written discourse showing agreement or
disagreement between 2 terms on the basis of a
common third term.
- an argumentation from 2 propositions called
premises, we arrive at a third proposition called
conclusion.
- must always have a sequential relation in
the presence of a middle term.

35. Observe the ff. propositions. Do they
constitute a syllogism? Why?
Every man is a biped
But every cow is a quadruped.
Therefore, every cow is not a man.
All creatures are mortal.
But a person is a creature.
Therefore, a person is mortal.

36. COMPONENTS OF A CTEGROICAL SYLLOGISM
Syllogism
Major Premise Minor Premise Conclusion
Major term (T), Minor term (t), Middle term (M)

37. Observe the following example:
Every flower is a plant. (Major Premise)
But a fish is not a plant. (Minor Premise)
Therefore, a fish is not a flower. (Conclusion)
T – flower
t – fish
M – plant

38. The three (3) terms in the premises must be
UNIVOCAL.
A President is a ruler.
But a ruler is 12-inch thing.
:. A 12-inch thing is a President.
Therefore is represented by :.