ABSTRACT
The a priori poses special problems for empiricism. The concepts of necessity, possibility and impossibility are modal notions and are metaphysical concepts, while the concept of analyticity is semantic. The concept of a priori is epistemological. Many philosophers argue that giving up the a priori comes at too high a price. Traditional empiricism holds that the theories of natural science and common sense move between two levels of unrevisable propositions. An analytic proposition, according to Kant, is one whose subject term contains its predicate term. Synthetic propositions go beyond the meanings of the terms and so are not trivially true. The chapter focuses on the objections of Mill and Peirce. Peirce holds that logical theories are hypotheses offered to explain the rules for judging valid arguments of a certain class, for example, arguments resting on subject-predicate relations, relations between propositions, relational arguments in general, or even modal characteristics.
