original determination of the Dasein's existence, regardless of whether the Dasein pursues science in the manner of explanation or of understanding. And what is more, in the end understanding is not at all primarily a cognition but—since existence is indeed more than mere cognition in the usual spectator sense of knowledge and such knowledge presupposes existence—a basic determination of existence itself. This, in fact, is how we have to take the concept of understanding.
Let us try to delineate this concept without as yet making explicit reference to the understanding involved in the understanding of being. How does understanding belong to the Dasein's existence as such, apart from whether the Dasein does or does not practice psychology or history as understanding? To exist is essentially, even if not only, to understand. We made some remarks earlier about the essential structure of existence. To the Dasein's existence there belongs being-in-the-world, and in fact in such a way that this being-in-the-world is occupied with this being itself. It is occupied with this being; this entity, the Dasein, has its own being in a certain way under control, as it comports itself in this or that way toward its capacity to be, as it has already decided in this or that way for or against it. "The Dasein is occupied with its own being" means more precisely: it is occupied with its own ability to be. As existent, the Dasein is free for specific possibilities of its own self. It is its own most peculiar able-to-be. These possibilities of itself are not empty logical possibilities lying outside itself, in which it can engage or from which it could keep aloof; instead they are, as such, determinations of existence. If the Dasein is free for definite possibilities of itself, for its ability to be, then the Dasein is in this being-free-for; it is these possibilities themselves. They are only as possibilities of the existent Dasein in whatever way the Dasein may comport toward them. The possibility is in every instance that of one's own most peculiar being. It is the possibility it is only if the Dasein becomes existent in it. To be one's own most peculiar ability to be, to take it over and keep oneself in the possibility, to understand oneself in one's own factual freedom, that is, to understand oneself in the being of one's own most peculiar ability-to-be, is the original existential concept of understanding. In German we say that someone can vorstehen something—literally, stand in front of or ahead of it, that is, stand at its head, administer, manage, preside over it. This is equivalent to saying that he versteht sich darauf, understands in the sense of being skilled or expert at it [has the know-how of it}. The meaning of the term "understanding" [VerstehenJ as defined above is intended to go back to this usage in ordinary language. If understanding is a basic determination of existence, it is as such the condition of possibility for all of the Dasein' s particular possible manners of comportment. It is the condition of possibility for all kinds of comportment, not only practical but also cognitive. The explanatory and understanding sciences-if this classification is admitted as being