The pursuit of airtight reasoning
Logic is the architecture of thought — the invisible scaffolding that holds an argument together. At logic.quest, we explore the timeless structures of reasoning: from Aristotelian syllogisms to modern propositional calculus, from paradoxes that break your intuition to proofs that restore it.
| P | Q | P ∧ Q | P ∨ Q | P → Q | P ↔ Q |
|---|---|---|---|---|---|
| T | T | T | T | T | T |
| T | F | F | T | F | F |
| F | T | F | T | T | F |
| F | F | F | F | T | T |
All men are mortal.
Socrates is a man.
∴ Socrates is mortal.
No reptiles have fur.
All dogs have fur.
∴ No dogs are reptiles.
All cats are mammals.
Some pets are cats.
∴ Some pets are mammals.
"This statement is false." If it is true, then it is false. If it is false, then it is true. The serpent eats its own tail.
⊥Does the set of all sets that do not contain themselves contain itself? The question that shattered naïve set theory.
∅Observing a green apple confirms that all ravens are black — by contraposition. A red herring dressed in formal logic.
¬Remove one grain from a heap of sand. Still a heap? Repeat. When does a heap cease to be a heap? Vagueness meets logic.
≈The most fundamental rule of inference. From "if P then Q" and "P", we derive Q. Simple. Elegant. Irrefutable.
Logic is not cold mathematics. It is a warm, human, deeply satisfying quest — the pursuit of clarity in a world of noise.