Introduction -- A pragmatic conception of the a priori / by C.I. Lewis -- The a priori / by A.J. Ayer -- Two dogmas of empiricism / by W.V. Quine -- Wittgenstein and logical necessity / by Barry Stroud -- Analyticity and apriority, beyond Wittgenstein and Quine / by Hilary Putnam -- The truths of reason / by Roderick M. Chisholm -- A priori knowledge, necessity, and contingency / by Saul A. Kripke -- Kripke on the a priori and the necessary / by Albert Casullo -- Analyticity, necessity, and apriority / by R.G. Swinburne -- Apriority and necessity / by Philip Kitcher.