Deductive Logic

Their are 3 kinds of deductive logics:Syllogisms, modus ponens and modus tollens.



A syllogism has 3 statements and 2 terms for each line. It has a major premise and a minor premise and then a conclusion.

Example:All sports help humans become physically healthy
Kobe is a human
Kobe is physically healthy

Modus Ponens is justified as

if P, then Q

P

Therefore, Q

Example:If Alex can hit, we'll give Derek batting practice
Alex can hit
Therefore, we'll give Derek batting practice

Modus tollens is justified as

if P, then Q

not q

Therefore, not q

Example:If you are rich you are wealthy, if you are not wealthy you are not rich