Summary of Theories of Truth
This is a very brief summary of the main theories of truth. For more comprehensive accounts, look up "truth" (or "epistemology") in the online philosophy resources!
1. The Correspondence Theory
The correspondence theory is the "default" theory of truth. It's the one most people think is obvious. According to the correspondence theory, a claim is true if it corresponds to what is so (the "facts" or "reality") and false if it does not correspond to what is so. Most scientists and many philosophers hold some version of the correspondence theory of truth.
Example: The statement "The opera Aida had its first performance in Cairo" is true just in case the opera Aida had its first performance in Cairo, and false otherwise. "Snow is white" is true just in case snow is white.
Problems: Is the correspondence theory itself true? If so, what does it correspond to?
How do we figure out what is so? This latter question belongs to metaphysics. A metaphysical realist will hold that the reality that "corresponds" is objective and mind-independent. An idealist may hold that it is objective yet not mind-independent.
You may think it is easy to figure out what is so. In the next Part of the class (Part 8), we will see the overwhelming psychological evidence that there is no such thing as "pure" perception or "pure" linguistic description. If everybody comes from somewhere, nobody has complete God-like objectivity. So some people have rejected the correspondence theory because they say we simply can't discover what is so in any "objective" way.
Think about this argument in the light of our earlier discussion of the subjective-objective distinction! (Remind me.)
(The point of our discussion was that you DON'T have to reject the correspondence theory of truth even if it's true that there's no pure perception.)
2. The Pragmatic Theory
According to the pragmatic theory, a statement is true if it allows you to interact effectively and efficiently with the cosmos. The less true a belief is, the less it facilitates such interaction. A belief is false if it facilitates no interaction. The most famous advocate of the pragmatic theory is the American philosopher William James. A contemporary adherent is Richard Rorty.
Example: My belief that inanimate objects do not spontaneously get up and move about is true because it makes my world more predictable and thus easier to live in. It "works."
Problems: Sometimes unreasonable beliefs "work". A tribe might believe that human sacrifice brings their crops back each year. The crops do come back after the human sacrifice, but not because of the human sacrifice.
The pragmatic theory of truth might invite relativism in the case of beliefs that are compatible with all states of affairs, e.g., religious beliefs. (Someone might say the belief "God exists" is true because it "works for me," i.e., it helps this person "interact more effectively with the cosmos.")
The notion of "more effective and efficient interaction with the cosmos" is objectionably vague.
The pragmatic theory of truth invites the notion that there are degrees of truth (some beliefs might be more effective than others), and thus invites us to reject the law of non-contradiction ("a claim is either true or false").
3. The Coherence Theory
According to the coherence theory of truth, a statement is true if it is logically consistent with other beliefs that are held to be true. A belief is false if it is inconsistent with (contradicts) other beliefs that are held to be true. We should doubt claims that are currently inconsistent with the rest of our beliefs. Willard Quine is a famous contemporary philosopher who advocates the coherence theory.
Example: we don't believe in solipsism primarily because it contradicts so many of our other beliefs.
Problems: a belief can be consistent with all our other beliefs and yet have no independent supporting evidence. For example, many metaphysical beliefs are consistent with all imaginable states of affairs (e.g., "the universe came into existence five minutes ago complete with historical records and memories").