Truth is usually understood to be the opposite of fiction. So what’s with the title of this show? Ken and John begin by noting that truth is a notion that’s not as simple as it seems. John thinks Aristotle basically had it right: “to say of what is that it is, and of what is not that it is not, is true.” This is a correspondence theory of truth. Ken, on the other hand, is concerned that such a view places too much emphasis on what we say rather than what is, and that truths about complicated concepts like morality and God cannot be accounted for. Then maybe, John responds, Aristotle was making an even simpler claim: to say something is true is to just say that same thing. Under a deflationist view, truth is an “approving growl” we attach to sentences we assert. But now, as Ken points out, truth seems vacuous! These worries lead our hosts to wonder: is there even such a thing as truth? Or is it just a convenient fiction?

Alexis is introduced, and he begins by highlighting the important role that truth plays in our language as an inspirer of debate. In the course of discussion, Alexis’s view of fictionalism eventually becomes clear; he believes that although it could be that, as pointed out by logical paradoxes, truth is incoherent, we should preserve it for its usefulness.

Alexis, John, and Ken also discuss how the correspondence theory might run into trouble in evaluating sentences about fictional characters like Santa Claus.  But a yet more pressing problem for the correspondence theory is that it’s proven difficult to come up with a good theory of reference – a theory that demonstrates how bits of sentences can be matched with bits of the world. John argues that there is widespread agreement on many cases of references, and in cases where we have difficulty with the match, we predictably have difficulty applying the concept of truth.

A slew of audience questions rounds out the show. Everything from fuzzy logic and degrees of truth to whether we should seek the truth is discussed. Despite Alexis’s persuasive arguments, John concludes by asserting his staunch continued commitment to the correspondence theory.

• Roving Philosophical Reporter (Seek to 6:37): Caitlin Esch explores the relationship between truth and fiction in art with novelist Nancy Horan, author of the historical fiction Loving Frank, and Mike Daisey, performer of the controversial one man show The Agony and Ecstasy of Steve Jobs.