• Bertrand Russell: "Truth is to be understood as some kind of correspondence between belief and fact."
• Aristotle: "To say what is so that it is not so, and to say that which is not so that it is so, is false; while to say of what is so that it is so, and of what is not so, that it is not so, is true."
• Eubulides of Megara: "what is the truth of the statement 'All generalizations are false'?" (itself a generalization)
• Aristotle: "It is true only if it is itself false, and false only if it is true!"

Correspondence Theory	fact	Nonfact
Belief	1 (truth). Belief in a fact, a correspondence of belief and fact, or truth.	3 (False Belief). We actively believe something that is not factual so we hold a false belief.
Nonbelief	2 (disbelief). Failure to recognize a fact, and therefore we do not see, or have, or believe the truth.	4 (Unknown). Not believing something that is not a fact. "We may not be aware that the object of disbelief is not a fact."