Tuesday, October 02, 2012

Casullo on Negative and Positive Approaches to Apriority

Chapter 1 of Al Casullo's book, A Priori Justification, explores various theories of a priori justification. In the penultimate step of the chapter, he's argued that the motivations behind various theories ultimately converge on two views -- one 'negative', and one 'positive'. This is from p. 31 (with his labels changed for simplicity):

  • (Neg) S's belief that p is justified a priori if and only if S's justification for the belief that p does not depend on experience.
  • (Pos) S's belief that p is justified a priori if and only if S's belief that p is justified by some nonexperiential source.
Thus stated, the negative characterization (N), Al says, is ambiguous, because of different ways in which justification can depend on experience. So (N) is disambiguated into:
  • (Neg-Weak) S's belief that p is justified a priori if and only if S's belief that p is nonexperientially justified.
  • (Neg-Strong) S's belief that p is justified a priori if and only if S's belief that p is nonexperientially justified and cannot be defeated by experience.
Of the three remaining views -- Pos, Neg-Weak, and Neg-Strong, Al goes on to claim that there are really only two, because Pos and Neg-Weak are equivalent. The rationale here seems to be the idea that  every justified belief has its justification due to a source, and any given source is either experiential or nonexperiential. Take a justified belief, and consider the binary question of whether its justification's source is experiential; Neg-Weak says yes if it is; Pos says no if it isn't.

But I think this bit of reasoning is too quick. I'm suspicious of the move from nonexperiential justification to derivation from a nonexperiential source. To equate Pos with Neg-Weak is to legislate in advance that for any justified beliefs, there is a source of its justification. That is to say, it assumes prior to argument that there is no original justification -- justification that does not depend on a source. But that there is such original justification is, it seems to me, a coherent view that occupies a spot in logical space. (For what it's worth, I also think it's true; Ben and I defend it in The Rules of Thought.)

Sources generate things that weren't already there. The assumption that justification for a priori justified belief must derive from a source is, I think, part of the motivation for supposing there must be some kind of faculty of intuition to serve as source.

I'm not sure whether there are nonexperiential sources of justification. But I'm firmly committed to beliefs that are justified in a way that doesn't depend on experience. If these two attitudes are jointly coherent, then Casullo is wrong to equate Pos with Neg-Weak.


  1. Dirk Koppelberg10/03/2012 02:53:00 AM

    Crucial is your distinction between justification from a source and original justification. Thus, according to your view, an original justification cannot be a justification from any sort of source whatsoever. What does this mean? Can you give an example?

  2. Here's one kind of possible example: Crispin Wright thinks that certain cornerstone propositions are justified by default; we don't have to earn warrant for propositions like -- we just have it automatically.

    Now maybe this isn't the best example, because maybe on Crispin's view, there is a source for that warrant -- just not an evidential one. (He offers a pragmatic justification; maybe that counts as a source.)

    The kind of example I've defended involves what I call 'rational necessities'. (These are approximately what other people have called 'analyticites'.) I think that these propositions are by their nature such that there is always conclusive justification to believe them. For example, is, by virtue of the proposition that it is, a proposition for which there is always conclusive justification to accept it.

    1. Dirk Koppelberg10/03/2012 11:58:00 PM

      With regard to the example due to Crispin Wright:
      I'm afraid that I do not understand what it might mean to have 'warrant automatically'. If it should turn out that there is a nonevidential source, e.g. a pragmatic justification, why ought we to take it as an epistemic justification?
      With regard to your proposal: Unfortunately, I'm not familiar with your concept of 'rational necessity'. Do you give arguments for the claim that they belong to a class of propositions that there is always conclusive justification to believe them? Do you regard your proposal as a kind of nonepistemic analysis (in Casullo's sense)?

  3. My point in this post wasn't to argue that there *is* any justification that doesn't depend on a source -- just to point out that this represents a possible view that gets short shrift by the way Casullo set things up. Lots of people think the Crispin-style view is a bad one for just the reason you suggest. I'm not defending it -- I'm just pointing to it as an example of a view with a certain structure.

    As for my view, my forthcoming book with Ben Jarvis is an extended argument for the existence of such always-justified propositions. No, my view isn't an example of a nonepistemic analysis in Casullo's sense; the theory of apriority is pretty much the same as (Neg) mentioned above, except that I consider propositional justification to be fundamental. There's also a theory of rational necessities, which are argued to be examples of a priori propositions; but this isn't nonepistemic either.