1. All men are mortal
2. Socrates is a man
3. Socrates is mortal

A deductive argument can provide logical certainty without providing useful information about the real world. For this reason sound deductions are recognized as “valid” rather than “true.” If any of the original premises are incorrect or absurd, the conclusion of the syllogism may be worthless despite its inescapable, internal logical consistency.

1. All women are mortal
2. Socrates is a woman
3. Socrates is mortal

1. All goats have six legs
2. Socrates is a goat
3. Socrates has six legs