The a Priori

1 Preliminaries Defining A Priority • BonJour says that two characteristics are definitive of a priority, one negative and one positive. The negative one is probably the more familiar: — " an a priori reason for thinking that a claim is true is one whose rational force or cogency does not derive from experience. " [BonJour, 2005, p.98] — This does seem at least closely related to Kant's definition of the a priori in the First Critique: " In what follows, therefore, we shall understand by a priori knowledge, not knowledge independent of this or that experience, but knowledge absolutely independent of all experience. Opposed to it is empirical knowledge, which is knowledge possible only a posteriori, that is, through experience. " [A2/B3] And it's also the definition that you'll find in Kripke's Naming and Necessity when he notes that many of the philosophers who came after Kant have been careless about distinguishing a priority from analyticity and necessity. (Roughly: something is a priori if it is known independently of experience, necessary if it could not have been otherwise, and analytic if it is true in virtue of meaning.) — What counts as experience? BonJour intends it to include: sense experience, including kinesthetic experience, but also introspective awareness of one's own thoughts, sensations and mental states. — BonJour notes that this definition is meant to allow that experience could be needed in order to understand the claim being made; it's the reason to believe the claim that has to be independent of experience: That such a reason is independent of experience does not mean that someone who has undergone no experience of any sort could be in possession of it, since the possession of an a priori reason requires understanding the claim for which it is a reason, and experience, even experience of some fairly specific sort, might be required for that. [BonJour, 2005, p.99] – The positive condition on a priority: — " in the most basic cases such reasons result from direct or immediate insight into the truth, indeed the necessary truth, of the relevant claim. " [BonJour, 2005, p.100] What are the objects of A priority? • In 'ordinary' philosophical conversation, we often attribute a priority to, or deny it of, propositions. For example, we say – It is a priori that triangles have three sides. – The proposition that snow is white is a posteriori.