"The Mystery of Apriority"
The concept of a priori does not belong to Heidegger’s favourite or most familiar concepts. Unlike concepts such as, e.g., Sein, physis, ousia, idea, aletheia, etc., it is not given detailed discussions in his works. When it occurs – mostly in the 1920s – it has the usual meaning it has come to obtain in early modern philosophy ever since Kant. A characteristic occurrence of the term crops up in his main work: “‘A-priorism’ is the method of every scientific philosophy which understands itself.” (“Der »Apriorismus« ist die Methode jeder wissenschaftlichen Philosophie, die sich selbst versteht” (Sein und Zeit, p. 50 = Being and Time, trans. John Macquarrie & Edward Robinson, p. 490, note x). To claim that this concept does not rank in Heidegger’s innermost vocabulary is, however, not to claim that he totally ignored or overlooked it. On the contrary: Heidegger was well aware that this concept is closely related to two of his most central concepts or themes: those of time and – through it – to Being. – The paper proposes to explore these dimensions in several subsequent steps. First it is shown that, in his critical confrontation of Husserl’s phenomenology, Heidegger appreciated very much Husserl’s efforts to reconstruct “the original sense of a priori” by disengaging it from the subject. Heidegger takes up and radicalizes Husserl’s effort to de-subjectivate this concept in claiming that a priori is a designation of being. Towards the end of the 1927 lecture course (=GA 24) Heidegger comes to expand on the theme more in detail. He says that the original sense of a priori in terms of “earlier” contains a clear reference to time; it is, therefore, a temporal determination. He claims that earlier than any possible “earlier” is time or temporality. This makes it possible to speak meaningfully about something such as “earlier” at all. Time may, accordingly, be called to be the “earliest” of everything that may come “earlier”– it is, indeed, the a priori of all possible a prioris, preceding these and making them possible. On the other hand, preceding all beings is being as such. Being is “earlier” than beings. From this perspective, Being is the absolute a priori. A priori is then both a temporal and an ontological concept. Time, however, understood in terms of its relation to being, is not to be accounted for by and in terms of the common concept of time in the sense of intratemporality. Philosophy as an a priori science is both an ontological and a temporal science, and that is what Heidegger’s main thesis according to which Being and Time belong together comes down to. – In subsequent parts of the paper a possible objection is examined at some length, namely, whether it is not a misunderstanding, on Heidegger’s part, to claim that “earlier” is always and in any case a “temporal” determination, whether, in other words, one could not – and indeed, should not – rather make a distinction between “temporal” and “logical” sequence or succession. This objection is countered with reference to the fact that, in order to reasonably formulate the dichotomy temporal–logical, one must tacitly presuppose a restricted, that is, non-Heideggerian concept of time. A final dilemma emerges with regard to whether and to what extent Heidegger’s assumption of his radically new concept of time can legitimately be linked to (or opposed to) traditional concepts of time – a dilemma pretty much the same as the ones regarding whether and to what extent his radically new concepts, e.g., of history and being, can be linked to, and derived from, a critical confrontation (=destruction) of the philosophical tradition. This dilemma is claimed to pertain to the linguistic dimension of philosophy (that is, of how, with what conceptuality a philosopher addresses or names his subject matter), and it seems hardly able to be overcome.