Priest, Graham - Truth And Contradiction

04/13/2007

The Philosophical Quaterly, Vol 50 Num 200 July 2000

Author begins by announcing that he is a dialethiest and believes that some contradictions can be true [or at least that not all contradictions are false?]. This is a claim about how to put together logic-- or what 'kind' of logic to endorse. [Logic is supposed to be a system of inferences that, if applied, are truth-preserving.] He doesn't argue directly for the appropriateness of dialetheism, instead is intent to show that the 6 front-running theories of truth (what makes something true if it is true) don't rule out dialethiesm. If none of the theories of truth particularly exclude dialetheism, then those who oppose such a logic will have to find some other resource to use to combat dialetheism. There are three traditional theories of truth, and three more modern ones. Author doesn't enumerate all the fine points of any of these theories, or even compare or contrast them; he simply gives minimal information about each and tries to show how it doesn't rule out dialetheism.

One caveat the author lays out is that there is a problem of what we're applying logic to: sentences, propositions, beliefs, statements, worldviews... what? Author says that nothing he talks about hinges on a specific restriction-- whatever the 'truth-bearers' are, that is what he will use-- he will use the Alpha symbol for this category.

(1) Deflationism
Deflationism says that was is true is the same thing as saying what is. This theory, author claims, has a tendency toward dialetheism, since certain paradoxes (the liar paradox) can lead to affirm a contradiction.

(2) Semantic Theory of Truth
This theory might have a problem in general if it uses a logic that allows anything to follow from a contradiction. For this, author suggests a paraconsistent logic that does not allow explosion. Once this happens, author claims this theory is consistent with dialetheism.

(3) Teleological Theory
We normally say 'x is true' to prove a point-- we aim at something when we say it. Author claims this is neutral when it comes to dialetheism.

(4) Pragmatist Theory
This theory says that something is true if it 'works', meaning perhaps it is verified in practice. This pragmatism can allow for inconsistent theories-- in fact ones that contain contradictions! Thus dialetheism is acceptable according to this theory as well.

(5) Coherence Theory
This one appears the most difficult, since 'consistency' in a model of truth seems to be immediately valuable. But here the author argues that there might be some virtues of a theory that are greater than consistency, and if so, the coherent theory must allow for an inconsistent but otherwise virtuous theory to be the true one.

(6) Correspondence Theory
Considered the most traditional theory, it says that something is true if it corresponds to reality. How exactly it can 'correspond' is the trouble here. Author sketches 'situational semantics', which is a system of logic that allows for context-specific truth values that might be ultimately contradictory if placed into a larger context, but avoid the difficulty by being contextual. The idea the author wants to avoid is the idea that the correspondence theory has to deal with a world or other maximally consistent set of objects to correspond to, not a smaller subset of things. The problem with this 'situational semantics' is that it allows for 'negative facts', or facts about what is not the case. This flies in the face of traditional correspondence theories like Wittgenstein's or Russell, since correspondence theories intuitively correspond to what is, not what isn't. But author argues that this is an arbitrary distinction.