3 INT. I
Being and Time

2. The concept of "being" is indefinable. This conclusion was [4] drawn from its highest universality.4 And correctly so—if definitio fit per genus proximum et differentiam specificam [if "definition is achieved through the proximate genus and the specific difference"]. Indeed, "being" cannot be understood as a being. Enti non additur aliqua natura: "being" cannot be defined by attributing beings to it. Being cannot be derived from higher concepts by way of definition and cannot be represented by lower ones. But does it follow from this that "being" can no longer constitute a problem? Not at all. We can conclude only that "being" ["Sein"] is not something like a being [Seiendes].* Thus the manner of definition of beings which has its justification within limits—the "definition" of traditional logic which is itself rooted in ancient ontology—cannot be applied to being. The indefinability of being does not dispense with the question of its meaning but forces it upon us.

3. "Being" is the self-evident concept. "Being" is used in all knowing and predicating, in every relation to beings [Seienden] and in every relation to oneself, and the expression is understandable "without further ado." Everybody understands: "the sky is blue," "I am happy," and similar statements. But this average comprehensibility only demonstrates the incomprehensibility. It shows that an enigma lies a priori in every relation and being toward beings as beings. The fact that we live already in an understanding of being and that the meaning of being is at the same time shrouded in darkness proves the fundamental necessity of retrieving the question of the meaning of ''being."

If what is "self-evident" and this alone—"the covert judgments of common reason" (Kant)—is to become and remain the explicit theme of our analysis (as "the business of philosophers"), then the appeal to self-evidence in the realm of basic philosophical concepts, and indeed with regard to the concept "being," is a dubious procedure.

However, consideration of the prejudices has made it clear at the same time that not only is the answer to the question of being lacking, but even the question itself is obscure and without direction. Thus to retrieve the question of being means first of all to work out adequately the formulation of the question.

* no! rather: a decision about beyng [Seyn] cannot be made with the help of such conceptuality.

4. Cf. Pascal, Pensées et Opuscules, ed. Brunschvicg (Paris, 1912), p. 169: "One cannot undertake to define being without falling into this absurdity; for one cannot define a word without beginning in this way: 'It is ...'. This beginning may be expressed or implied. Thus, in order to define being one must say 'It is ...' and hence employ the word to be defined in its definition."

Martin Heidegger (GA 2) Being & Time (S&S)