logic and Truth Relations of sentences. Necessary truth, contigent truth, priori truth, posteriori truth, analytic and synthetic truth

1. SEMANTICS
Presentation topic: sentence
relations and truth

2. LOGIC AND TRUTH RELATIONS
1.Modus Ponens
•The way that affirms by affirming
a) All humans are mortal.
b) Socrates is human.
c) therefore, Socrates is mortal.
•c) is affirming a) and b).

3. 2. Modus Tollens
The way that negates by negating
a) if something is human then it is mortal.
b) Zeus is not mortal.
c) Zeus is not human.
•c) is negated by negating a) and b).

4. OTHER TYPES OF SYLLOGISM
3. Hypothetical syllogism
a) if something is human then it is mortal.
b)if something is mortal then it dies.
c) if something is human then it dies.

5. 4. Disjunctive syllogism
• also called Modus Tollendo Ponens i.e.,
affirms by denying
a)Either a human is mortal or a human is
immortal.
b)A human is not immortal.
c)A human is mortal.
c) Is confirmed by denying b).

6. THREE TYPES OF TRUTH RELATIONS
1. Arguments from the speaker’s knowledge,
Priori Truth
A Priori Truth is truth that is known without experience.
e.g. My name is Anna.
Posteriori Truth
A Posteriori Truth is truth known from empirical testing.
e.g. Sawat is the Paris of Pakistan.
A priori/posteriori truth concerns the source of what
the speaker knows

7. 2. Argument from the facts of the world,
Necessary Truth
is truth that cannot be denied without forcing a
contradiction.
e.g. God is one.
Sun rises in the east.
Contigent Truth
can be contradicted depending on the facts.
e.g. Aleena is not actually a good girl.
Metaphysical one, we philosophically question the
nature of reality.

8. 3. Arguments from out model of the world.
Analytic Truth
follows from meaning relations within the sentences,
need to know word meaning.
Analytic truth related to tautology.
e.g. My father is my father.
Synthetic Truth
agrees with the facts of the world.
e.g. My father is a sailor.
The analytic/synthetic truth distinction is semantic in
orientation.

9. •Thank You