Dialetheism and What Sorts of Things are True?

I recently listened to a bunch of podcasts by the logician Graham Priest who is an important contemporary advocate of dialetheism, the view that a sentence can be true and not true.   I find it convincing, but it raises a question.  How are we supposed to relate to something that is true and not true?

How do I relate to “p and not p”?

Well, if you think about it, we relate to the marks above “p and not p” by contextualizing them in a human relationship.  Looking at the marks on the screen above you know that they are a step in a discussion of logic, that another person (me, hi!) is putting out there to foster a dialogue.

In general we are trained to think that the things that are true and false are sentences.  But sentences are only true or false really if they are being used to express a speech act of assertion.   And a speech act of assertion is true or false in a particular context — Bob asserting to me “it is raining outside” is true if it is in fact raining outside where the two of us are.

“True” is cognate to “trust” and to say that Bob’s assertion “It’s raining outside” is true is really to say that I trust it, which is to say, I trust Bob in this context.  (Sometimes people try to say “true” means “corresponds to the facts” but this is just a circular move, since to state the facts we need some speech acts of assertion, so to say that “p is true” means “p corresponds to the facts” explains nothing.)

So to say that sometimes things are true and not true are to say that some people we trust and do not trust.  And this is something not mysterious at all.

Let’s not take an emotionally charged example like love, where I trust someone to turn me into a new human being or to go on a self-transforming journey together in which we lose ourselves.  Let’s take a very simple request for attention.

“Hey” says my friend or teacher or older brother “This is worth thinking about.   This is worth looking at.”

Do I trust this or not?  I do and I don’t.  I don’t just give up what I am currently paying attention to, but I do trust the person enough (if I do) to commit myself to the stream of his or her attention and see where it takes us.

The statement “Hey pay attention to this” in the context of most relationships is true and not true, meaning I trust it and I don’t.

And this far from being weird or impossible to make sense of, happens all the time.







7 thoughts on “Dialetheism and What Sorts of Things are True?

  1. Interesting thoughts. I’d never heard of dialetheism. Based on what you said, it’s unobjectionable but I’m not sure what’s new about it. Aristotle would have agreed that p can be true in one respect and false in another, which seems to be what the idea is getting at.

    However, your suggestion that truth and falsity aren’t limited to sentences is along the lines I’ve recently argued, that meaning, justification, and truth can be different things in different contexts but they all boil down to the same thing: connection. Clouds mean rain. “It’s raining” means it’s raining. “Fine” at the end of an argument with your wife means you’re in the doghouse.

    “Trust me” often means “don’t trust me,” and since both are imperatives, they’re true in the same way. I think we can trust everyone to be exactly what they are and to act accordingly. The problem is that we often misjudge what they are. Trust requires us to understand the other people correctly. It’s harder than you’d think. 🙂

  2. actually dialetheism doesn’t say that p is true in one respect and not p is true in another respect. it makes the more radical claim that in some cases p is true and p is false full stop. The clearest example of a true-and-false statement is the liar sentence “this sentence is false”.

      • So, ‘Here’s this great investment opportunity that gives massive returns’…you just trust it, rather than check if it’s a ponzi scheme?

        I mean, how can you be trusting someone but at the same time backing out of ‘investing’ your hard earned into the patently obvious ponzi?

        It doesn’t sound like true and false at the same time, it just sounds like being diplomatic and being skeptical at the same time. Which on a side reflection I might not be doing myself, but I figure this is a place where we talk fairly straight since diplomacy often gets in the way of genuine philosophy (or so I think – maybe I’m wrong)

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