Logic takes care of itself; all we have to do is to look and see how it does it.

Contradiction is not a sign of falsity, nor the lack of contradiction a sign of truth. But contradiction reveals where thought has failed.

The logic of the world is prior to all truth and falsehood. The world is everything that is the case.

Logic is the hygiene the mathematician practices to keep his ideas healthy and strong.

All men make mistakes, but a good man yields when he knows his course is wrong, and repairs the evil. The only sin is pride in error.

Logic is the anatomy of thought. It reveals the skeleton of reasoning beneath the flesh of language.

In logic, nothing is accidental: if a thing can occur in a state of affairs, the possibility of the state of affairs must be written into the thing itself.

The limits of my language mean the limits of my world. Logic fills the entire universe, so too the limits of my logic mean the limits of my understanding.

Logic is the foundation of certainty, but certainty is not the foundation of knowledge. The map is not the territory.

A logical system must be tractable, otherwise it is useless for human thought. The perfect system would be one in which all true statements were provable, but such a system is impossible.

Logic is the art of going wrong with confidence. But it is also the art of recognizing when you have gone wrong.

The first rule of logic: to be willing to surrender any belief, no matter how cherished, if the evidence demands it.

Logic is neutral. It can be used to prove truth or defend falsehood with equal rigor. The difference lies in the premises.

In nature, there are no rewards or punishments; there are consequences. Logic is the study of these consequences in thought.

The chains of logic are too light to be felt until they are too heavy to be broken. Build your chains carefully.

Logic is the sword of truth, but it cuts both ways. It can defend wisdom or entrench foolishness with equal precision.

A valid argument can have a false conclusion if it begins with false premises. Logic guarantees only that if the premises are true, the conclusion must be true.

The purpose of logic is not to find truth, but to preserve truth across inferences. It is the machinery of reasoning, not the source of knowledge.

Logic is the grammar of thought. Just as grammar rules govern language without determining content, logic rules govern reasoning without determining truth.

In logic, the most dangerous errors are not the obvious fallacies, but the subtle ones that appear reasonable at first glance.

Logic is the foundation, but intuition is the architect. One without the other builds either unstable structures or uninhabitable ones.

The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function logically.

Logic is the art of thinking clearly, but clarity is not always truth. A clear error is still an error.

In the realm of logic, possibility is cheap. What matters is what is necessary, what must be the case given what we know.

Logic is the great clarifier. It cannot create knowledge, but it can expose ignorance and inconsistency with merciless precision.