Ultimately, as Heidegger demonstrates in his 1955–1956 lecture course, The Principle of Reason, the principle of reason self-deconstructs because it cannot apply to itself its own requirements without undermining itself: if the principle of reason states that everything that happens must have a reason, then what is the reason for the principle of reason? Does the principle of reason have a reason? “Indeed the principle of reason is, as a principle, not nothing. The principle is itself something. Therefore, according to what the principle itself tells us, it is the sort of thing that must have a reason. What is the reason for the principle of reason?” (GA 10, 17/PR, 11). Does the principle of reason have a reason? Nothing could be less certain. “Nihil est sine ratione. Nothing is without reason, says the principle of reason. Nothing—which means not even this principle of reason, certainly it least of all. It may then be that the principle of reason, that whereof it speaks, and this speaking itself do not belong within the jurisdiction of the principle of reason. To think this remains a grave burden. In short it means that the principle of reason is without reason. Said still more clearly: ‘Nothing without reason’—this, which is something, is without reason” (GA 10, 27/PR, 17, emphasis mine). One divines here how the principle of reason is caught in a circle (What is the reason of the principle of reason? What is the foundation of a foundation?) that will throw it into a self-deconstruction, that is, into the abyss of its own impossible foundation.
Indeed, in order to be a ground, the ground must itself be without foundation and therefore groundless. This led Gilles Deleuze to speak of the paradoxical nature of the logic of grounding, of the “comical ungrounding” of the principle of reason: “But who still speaks of a foundation, when the logic of grounding or the principle of reason leads precisely to its own ‘ungrounding,’ comical and disappointing.”4 The principle of reason does collapse (“run aground”) at the very place of its impossible foundation, “there where,” as Derrida puts it in Rogues, “the Grund opens up onto the Abgrund, where giving reasons [rendre-raison] and giving an account [rendre-compte]—logon didonai or principium reddendae rationis—are threatened by or drawn into the abyss.”5 Heidegger revealed this self-deconstructive aspect of the principle of reason by following the logic of the question “why?”: “Whenever we pursue the ground/reason of a being, we ask: why? Cognition stalks this interrogative word from one reason to another. The ‘why’ allows no rest, offers no stop, gives no support” (GA 10, 185/PR, 126, my emphasis). The question “why?” seeking a foundation, in fact reveals an abyss, betraying that reason itself may lack a rational basis. Kant spoke of reason as a drive, a Trieb, of an “interest” of reason (Interesse der Vernunft), thereby pointing to a certain nonrational basis of reason, which led Derrida to ask: “The honor of reason—is that reason? Is honor reasonable or rational through and through? The very form of this question can be applied analogically to everything that evaluates, affirms, or prescribes reason: to prefer reason, is that rational or, and this is something else, reasonable? The value of reason, the desire for reason, the dignity of reason—are these rational? Do these have to do wholly with reason?” (R, 120). Is reason rational? Is the principle of reason rational? Does reason have a reason? These questions reveal the aporia harbored in the principle of reason.
In fact, each time unpredictable and incalculable, an event always exceeds or “suspends”6 the demands of the principle of sufficient reason. As Jacques Derrida states, an event can only challenge the principle of sufficient reason “insofar as reason is limited to ‘giving an account’ (reddere rationem, logon didonai).” It is not a matter of complying with the demands of such reason rendering, but instead of not “denying or ignoring this unforeseeable and incalculable coming of the other.”7 No longer placed under the authority of the principle of sufficient reason, the event must be rethought as the incalculable and unpredictable arrival of what will always remain other—and thus inappropriable—for the one to whom it happens. In that sense, the event also comes as an excess in relation to the subject and can only “naturally take by surprise not only the addressee but also the subject to whom and by whom it is supposed to happen.”8 It would then be a matter, in order to give thought to the event in its eventfulness, of freeing the event from the demands of the principle of sufficient reason.
A clarification is necessary at the outset: by the project of “thinking the event,” I do not mean the appropriation by thought of the event, under the authority of the principle of reason. Thinking here is not appropriative, not “in-scription,” but rather, as Jean-Luc Nancy calls it, “ex-scription.”9 The event remains outside of thought, “exscribed” in it. “Thinking the event” means to give thought to its very eventfulness, its sheer happening, which necessarily exceeds both reason and subjectivity. Indeed, one could say that the event, in its disruptive and unpredictable happening, exceeds both the concept and the anticipation of a subject. This is why a further obstacle in the attempt to think the event is the predominance of transcendental modes of thought, which claim to provide prior conditions of possibility for experience and for the occurrence of events. Indeed, it may well be the case that events are precisely eventful when not preorganized or prepared by some transcendental conditions, or anticipated by a transcendental subject, when they break or “pierce” the horizon provided by transcendental conditions. Not being made possible by a prior condition, the event, as Jean-Luc Nancy points out, “must not be the object of a programmatic and certain calculation. . . . It must be the possibility of the impossible (according to a logic used often by Derrida), it must know itself as such, that is to say, know that it happens also in the incalculable and the unassignable.”10 An event cannot be reduced to what can happen: it does not happen because it can happen, but rather happens without being made possible in advance and to that extent can be called “impossible,” Jean-Luc Marion going so far as to state that the event can only be impossible, the impossible itself: “Moreover, [the event] always appears to us at bottom as impossible, or even as the impossible, since it does not belong to the domain of the possible, of that of which we are able.”11 The impossible, in this context, does not mean what cannot be or happen. Rather, the impossible, or the im-possible, as Derrida writes it, means: that which happens outside the conditions of possibility offered in advance by a subject of representation, outside the transcendental conditions of possibility. Thinking the event will require to break with a certain transcendental mode of thinking, as the event deconstructs the transcendental as such.
In the philosophical tradition, the notion of event has been neutralized under the authority of reason and causality. With Kant, the event is conceived in terms of and on the basis of causality, its independence reduced to a causal order. As one knows, Kant assumes the universal determinism of nature, a universal causal determinism for everything that happens and according to which “everything in the world happens solely in accordance with laws of nature.”12 Such universal natural causality is taken by Kant as a given and not in dispute. This is not surprising, if it is the case, as Heidegger argues in The Essence of Human Freedom, that “Causality, in the traditional sense of the being of beings, in common understanding as in traditional metaphysics, is the fundamental category of being as