The question of existence, the “is” which defines being, dominates Heidegger's work, from Being and Time to the later reflections on language, poetry, science and philosophy. Being must be understood here as a verb, as expressing how things proceed forth in their existence. The manner of being which such questioning continually approaches is not that which defines this or that particular being (entity), but rather the “being of beings”, the is-ness which properly belongs to all beings. This is what differentiates the “being question” (Seinsfrage) as it historically unfolds in the care of philosophy from the particular “calculative” questions about the nature of the world which are posed by science.
But the very basis of this division between the being question and science itself bears testimony to the importance of the human as Dasein (“being here”), or that being for whom its own being is a fundamental concern. Dasein, the human, has available to it as modes of its own being both the possibility of enquiring into the qualities of other beings (concerning their “whatness”) and that of turning to question its own ontological constitution. This latter mode of being proper to Dasein Heidegger calls Existenz. Existenz (usually somewhat narrowly translated as existence) is one of the many “ontical affairs” of Dasein. By this Heidegger means that fundamental enquiry into existential matters is itself approached by way of the kinds of everyday quotidian concerns and questioning which characterise much of lived experience. The understanding garnered by this more mundane questioning he calls existentiell:
Heidegger's way forward is to explore the various senses in which correctness (that is, accordance) may occur. All imply a fundamental relationship between an act of presenting and the presentation of some thing itself. Presentative acts, such as statements or propositions, must “let the thing stand opposed as object” (Heidegger, 1993a, p. 121). They allow matters to stand as they are in themselves. In order to do this presentative acts must take an “open stance”, meaning they must allow themselves to be directed towards what is “opened up” in the thing which stands. This Heidegger calls comportment:
Comportment stands open to beings … All working and achieving, all action and calculation, keep within an open region within which beings, with regard to what they are and how they are, can properly take their stand and become capable of being said. This can occur only if beings present themselves along with the presentative statement so that the latter subordinates itself to the directive that it speaks of beings such-as they are. In following such a directive the statement conforms to beings. Speech that directs itself accordingly is correct (true) (Heidegger, 1993a, p. 122).
Presentative acts which adopt proper comportment are necessarily correct because they allow themselves to be directed to what is opened up in beings. Thus are they true. Note also that Heidegger does not here make a distinction in this regard between calculation - what we have discussed as informing - and other forms ...