In the second part of his essay, Heidegger addresses the question, “What task is reserved for thinking at the end of philosophy?” The thinking that he has in mind is neither science nor metaphysics, but is something new. “This thinking in question here necessarily falls short of the greatness of the philosophers. It is less than philosophy. Less also because the direct or indirect effect of this thinking on the public in the industrial age, formed by technology and science, is decisively less possible for this thinking than it was for philosophy” (p. 436). So this thinking is something that will appear to us as something very humble. It will not have the grandeur of the philosophy of the past. Moreover, in a technological age, it will seem to have no effect. Nonetheless, it is the highest possibility for human thought.
About what will we be thinking? Here Heidegger writes, “When we ask about the task of thinking, this means in the scope of philosophy to determine that which concerns thinking, is still controversial for thinking, and is the controversy. This is what the word Sache [matter] means in the German language. It designates that with which thinking has to do in the case at hand” (p. 437). Usually this leads us to a certain class of objects (e.g., geometry which thinks about figures). But if we take a certain realm of beings, then this will already be some subordinate mode and not the primordial Being.
On pages 437-440, Heidegger says that both Hegel and Husserl fail to think what comes first. After this discussion, Heidegger gives his own answer, viz., the “clearing,” as to the matter that we must think, “But what remains unthought in the matter of philosophy as well as in its method? Speculative dialectic is a mode in which the matter of philosophy comes to appear of itself and for itself, and thus becomes present [Gegenwart]. Such appearance necessarily occurs in luminosity. Only by virtue of some brightness can what shines show itself, that is, radiate. But brightness in its turn rests upon something open, something free, which it might illuminate here and there, now and then. […] We call this openness that grants a possible letting appear and show ‘clearing’” (p. 441). Past philosophy has been speculative dialectics in which the matter of philosophy comes to appear and becomes present. Those from Plato on, have made things become present to themselves. They let something appear, but there is something that has to precede that presencing. So what Heidegger wants to say is that the philosophers of the past were not getting to the highest things. Something had to make present this presencing—this something is the “clearing which allows the movement of speculative thought to become present in the first place. There must be a brightness, a light to come forth in the clearing. Clearing refers to a clearing in the forest—in the clearing, the light can shine in and things can become present.
The problem in Western philosophy is that it will only allow presencing. The clearing, however, is not a thing; it is the openness that allows the rocks and trees to become present. So Heidegger says, “it is necessary for thinking to become aware of the matter here called clearing. […] What the word designates in the connection we are now thinking, free openness, is a ‘primal phenomenon’” (p. 442). Philosophy as metaphysics is trying to make things present to us and that philosophy has reached its natural end in giving itself over to the sciences. The task now is to abandon that type of philosophy and embrace the clearing. As Heidegger points out, the natural sciences and philosophy depend on this “primal phenomenon,” but they are unable to recognize it because they only think of what is present.
According to Heidegger, only Parmenides thought and spoke of the clearing. Heidegger then quotes Parmenides’ poem, On Nature, where the goddess says, “but you should learn all: the untrembling heart of unconcealment, well-rounded, and also the opinions of mortals who lack the ability to trust what is unconcealed” (p. 444). So the goddess advises Parmenides to learn of the unconcealment [aleithia] and the opinion [doxa] of mortals. Heidegger is interested in the unconcealment which is another way of talking about the clearing. Interestingly, these are both negative terms—they are defined by the absence of something. In other words, the clearing is where the trees are not, and likewise unconcealment is the absence of what conceals. Parmenides, Heidegger thinks, made that unconcealment explicit for thought. However after him, it was covered over and we must make it explicit again.
As mentioned previously, the Greek word aleithia means unconcealment, yet it has come to be translated at “truth.” “Why is aletheia translated with the usual name, with the word ‘truth’? […] Insofar as truth is understood in the traditional ‘natural’ sense as the correspondence of knowledge with beings, demonstrated in beings, but also insofar as truth is interpreted as the certainty of the knowledge of Being, aletheia, unconcealment in the sense of the clearing, may not be equated with truth” (p. 446). Truth for us has become associated with the problem of presencing—“the correspondence of knowledge with beings.” So traditionally understood truth is when the knowledge present correspondes to being. However, this is not what unconcealment is. The word truth cannot be used to describe the clearing. In sum, the task of thinking at the end of philosophy is to make explicit what was explicit at the beginning. For Heidegger, the whole course of Western history from Plato onwards is a progressive concealment of what is truly first—what the Being of beings is—this stems from the attempt to make things present to us. One might even say that by the time we get to Kant, presencing is the only thing that we have. So to overcome this, we have to think of something that is not “presence-able”—something not graspable. We have to think about Being in the sense of clearing—the Being which is also a nothing. The clearing is only recognized by the fact that it excludes certain things—like darkness—so that light can be seen.