It is a being disposed [Gestelltsein] toward the beings of the world that disposes over the look [Aussehen] of those beings. Ἐπιστήμη is a ἔχις of ἀληθεύειν (b31). In this ἔχις the look of beings is preserved. (GA 19, 32)
This mode of preservation, however, by its very nature entails that the beings accessible to it and known in this way "can never be concealed." They cannot become other in their essential being, even when they are not purely present to our contemplation. "Scientific" knowing thus fundamentally denies the possible self-concealment of beings in its claim to knowledge, even though it must presuppose that very concealment as its own raison d'étre. The broader implications of this will become apparent as our study progresses.
In addition to being a ἔχις of disclosure or discovery, ἐπιστήμη is a ἔχις of demonstration. It proceeds by deduction or "syllogism" rather than by induction (ἐπαγωγή), since the knowledge pertaining to ἐπιστήμη can be taught, and "all teaching proceeds from that which is already known." In other words, ἐπιστήμη presupposes our already being in explicit possession of certain ἀρχαί (NE, 1139 b18).15 As learnable and teachable, ἐπιστήμη constitutes an independent kind of knowledge—its λόγος remains true whether or not its objects are present for it, and yet precisely because of this it does not in itself provide access to the ultimate disclosedness or true being of its objects (GA 19, 31f.). Such truth can be apprehended only by νοῦς, for it concerns a truth of being and not merely a "logical" or apophantic truth.
The second form of knowledge Aristotle considers is τέχνη, here understood in the restricted sense of know-how that pertains to making or producing. Τέχνη has as its object something that undergoes change. Its object (the product) undergoes change in the specific sense that prior to the productive process it does not yet exist in its eventual form. In this sense, the object of τέχνη is something that can be other than it is. Τέχνη, like ἐπιστήμη, entails a kind of θεωρεῖν, but one specifically concerned with how to bring a thing into existence (NE, 1140a13). Yet unlike ἐπιστήμη, this kind of seeing apparently contains the ultimate ἀρχή of its object within itself. Heidegger here refers to Aristotle's account from Book V Il of the Metaphysics. Before producing something, a kind of deliberation is required which entails that the artisan must first contemplate how the product will look in its εἶδος. In the Metaphysics, Aristotle states that "that which properly produces [τὸ ποιοῦν], that from which movement [κίνησις] begins, is the εἶδος in the soul" (M, 1032b22). More precisely, it is the 'seeing" of this εἶδος, its presence in the soul, which is there referred to
15 Cf. NE, 1140 b31f. For a more detailed account, see Posterior Analytics, 99 b15ff.