Heidegger has always sought to properly avoid (vermeiden) the ensarements of Hegel's historical thinking, and for just this reason Heidegger's thought regarding history, from Destruktion to Seynsgeschichte, has always respected Hegel's acknowledgment of the necessity that anyone asking the question of the meaning of history be beset from the outset with the immanent criticism of his own historical predjudices at work in the posing of this question. In short, Hegel's Universal History was the first to carry itself out in constant awareness of this limit, and Heidegger's Seynsgeschichte does not fall prey to some retrogressive naivete regarding the matter. Thinking regarding history must be historically situated; one cannot consider history save from within history ---nor is it, according to both thinkers and for drastically different reasons, desirable to even try to do so.
Keeping this necessity of immanent criticism in mind then, I would like to refine one of my own previous considerations of a crucial aspect of Seynsgeschichte that I articulated more than a year ago in a great discussion here. The aspect under consideration is Das Selbe. Previously I had tried to give a formal sketch of Das Selbe --an attempt destined for a certain kind of failure. But now I would like to offer a step toward a more concrete consideration of Das Selbe. Previously, I had offered the following gloss:
The Same is the name for Being as it has been granted throughout each epoch. But each epoch understands Being differently. The Same, therefore, does not designate an identity among epochal sendings of Being, nor does it designate another underlying thing (subjectum) in terms of which the unity of the epochs can be thought. Rather the Same designates that in terms of which each epoch may be called an epoch, or in other words, that in terms of which each epoch differs from the other yet remains epochal. What is this? It is the ἐποχή, that is, the withholding of the beginning which is proper to the beginning, and which destines in advance all possible epochs. The identical requires the present. The Same, unlike the identical, is that which cannot any longer be grasped now, in the present age, but rather lies in our future as the beginning. The Same is thus the still unthought jointure in terms of which the epochs are related. It is therefore a unity that can account for the plurality without reducing it to some one present thing. The attempt to say the Same explicitly must accordingly necessarily diversify itself.
I do not quote myself to be redundantly self-approving, but to point out an inherent shortcoming of this previous characterization. What the above sketch misses is the requirement that, if das Selbe is to be thought appropriately, it must be thought from out of the current age --and when we do this we avoid the tendency to think of it emptily in a mere formal logical fashion. Das Selbe is now --that is to say in the present age, the non-identical unity of Sein and Nichts. This very timely definition must be understood in terms of a state of affairs that has persisted, as it were, throughout Beyng's history, namely, that what das Selbe designates is that which has, up to the present time, always referred to both "Being as such" (i.e. that Sein which is understood in a seinsverstaendnis) and "Beyng itself" (that which is not yet understood in and as "Being as such"). In fact, it refers more precisely to this "and", their very conjunction. What sort of conjunction is this? When we speak in terms of beings, "the same" almost always designates a relation between two things. By contrast, when we speak in terms of Being, "the same" refers to a difference within Being itself, namely, the difference opened up by Being sending itself.
If it is true that to speak of Das Selbe in the current age is to speak of the dangerous coincidence of Sein and Nichts, then this is so only because the present understanding of Being has been given Nothing to understand. In keeping with the duality that results from the opening between Being as such and Beyng itself we must hear this last assertion in the full range of its ambiguity.
"The present understanding of Being has been given Nothing..."
This means first the present age has been refused a grant of Being which would enable a succeeding epoch to subsequently take its place. Because the present age has been given nothing it is also the last age, the age which ends the ages. However, just as soon as we admit this meaning of our assertion we must immediately consider another meaning --namely, that the present age, having been given Nothing to understand, has been assigned a peculiar mandate, indeed, has been given (geben) nothing but an auf-gabe, in order even to properly take place as an age at all. The two meanings of this assertion, dangerously coinciding in the same words, could hardly be in greater strife with one another. One claims the age has been left without a future, the other claims that it is precisely nothing other than this future which the present age must claim in order to be itself. However this apparent opposition is only a semblance resulting from the unique confluence of Das Selbe. For, to be given Nothing to think, i.e. to be thoughtlessly commanded by what is no longer present, namely Gestell, is to be offered the perilous possibility that we must, in a manner unprecedented, think precisely what this Nothing itself is. If we have nothing to think about in the present age, then we may no longer take even this Nothing for granted. Nothing now becomes the present form of what must still be thought as Being itself (Seyn). For this reason, Being and Nothing can never be considered identical, but they may be called the Same, das Selbe.