Knowledge, Belief, and the A Priori

Abstract

The notion of the a priori underwent several changes\ud since the time it came into existence in the Middle Ages.\ud Originally it had been used to mark a certain form of\ud argument, an argument that proceeds from what is prior to\ud what is later, from cause to effect: demonstratio procedens\ud ex causis ad effectum = demonstratio a priori. But this\ud changed with Kant, for whom it meant not a form of\ud argument but rather some special kind of knowledge (or\ud elements thereof), namely knowledge that (a) is independent\ud of particular experiences and (b) that makes experience\ud in general (Erfahrung überhaupt) possible. Tied up\ud with consciousness and the transcendental unity of\ud apperception, Kant"s understanding of the a priori was in\ud the spirit of his transcendental philosophy. But this\ud understanding changed again with the rise of analytic\ud philosophy, in which we still find the first characteristic but\ud not the second anymore. The idea of Erfahrung überhaupt\ud was given up, partly because one naturally wondered what\ud exactly this notion of experience in general, or experience\ud universally conceived, should be. Where should we get it\ud from, if not by way of abstraction and generalization from\ud individual cases of experience? And would this not make it\ud an empirical concept, so that the whole project of asking\ud for the conditions of its possibility would not lead us to the\ud kind of certainty, necessity and universality we expect from\ud a priori knowledge? There would be no guarantee that in\ud the future we would not make discoveries that would give\ud us new kinds of experiences or that would show us our\ud experiences in a new light. Thus, we would have to admit\ud that these experiences did not satisfy the conditions of\ud experience we had set up originally. The a priori conditions\ud would have to be revised