Science and the A Priori

With some trepidation I have posted a draft of my paper "A Priori Contributions to Scientific Knowledge". The basic claim is that two kinds of a priori entitlement are needed to ground scientific knowledge. I find one kind, called "formal", in the conditions on concept possession, and so here I largely follow Peacocke. For the other kind, called "material", I draw on Friedman's work on the relative a priori.

Even those not interested in the a priori might gain something from the brief case study of the Crowe et. al. paper "A Direct Empirical Proof of the Existence of Dark Matter". What is intriguing to me about this case is that the "proof" works for a wide variety of "constitutive frameworks" or "scientific paradigms" in addition to the general theory of relativity. I would suggest that this undermines the claim that such frameworks are responsible for the meaning of the empirical claims, such as "Dark matter exists", but I would still grant them a role in the confirmation of the claims.

Update (July 10, 2009): I have removed this paper for substantial revisions.

Kinds of A Priori Justification

In A Priori Justification, Casullo presents a minimal conception of the a priori as simply nonexperiential justification. This, in turn, is explained negatively as justification that does not arise due to the operation of the five senses. This clearly leaves open the possibility that there are several different kinds of a priori justification, but nearly all advocates for the a priori that I can find seem to assume that there must be a single, unified source.

A notable exception is Pap's 1944 article (Phil. Rev. 53: 465-484), although he weakens the plausibility of his three-fold distinction by concluding that the different kinds of a priori can easily intermingle.

Why not take a harder line and insist that there are different kinds of nonexperiential justification? One thought would be that some a priori justification is absolute because it is tied to conditions on concept possession, as with Peacocke, while some a priori justification is relative because it is tied to constitutive frameworks, as with Michael Friedman. Maybe this is the best way for the defender of the a priori to take on the radical empiricist.