DASEIN AND THE PRECURSORY QUESTION OF TRUTH | 109
traditional model, while the latter are derived from and explained by the former. In fact, articulating these originary structures means articulating that which enables the derivative elements of truth to be what they are, that is, the essence of truth. Clarifying that entails clarifying the being of truth, or, as Heidegger puts it, ‘our investigation will make it plain that to the question of the “essence” of truth, there belongs necessarily the question of the kind of being which truth possesses’.25
We usually consider intellectus and res to be different kinds of things, so with regard to what do they agree when in a relation of adaequatio? What grounds their relation such that adaequatio is possible? In an historically standard epistemology, one has knowledge (as opposed to falsity, illusion, or opinion) when one has truth together with justification. Such knowledge is manifest in judgements (subject predication), which are formulated linguistically in assertions/propositions (Aussage) or claims (Sätze). But ‘in judgment one must distinguish between the judging as a Real psychical process, and that which is judged, as an ideal content’.26 In turn, both of these must be distinguished from ‘the Real Thing as that which is judged about’.27 We have truth when the ideal content of a judgement has a relation of agreement to the real thing.
According to Heidegger, this model is insufficient and the reason can be seen in ‘the ontologically unclarified separation of the Real and the ideal’ or, inversely, the model’s inability to say whether the relationship of agreement between ideal content and real thing is itself ‘Real or ideal in its kind of being, or neither of these’.28 Thus the question becomes, ‘how are we to take ontologically the relation between ideal entity and something that is Real and present-at-hand?’29 To pose the question in the general terminology of adaequatio, what is the ontological character of the relation between intellectus and res? Heidegger’s solution entails a rejection of the fundamentality of the epistemological model supporting this version of the real/ideal distinction. The absolute distinction between real judgement, ideal content, and real thing is sustainable only so long as a system fails to discern the fact that the relation between judgement and thing, or between
Heidegger argues that to clarify the being of this relation (that is, the essence of truth) we can examine the way ‘knowing demonstrates itself as true’; in other words, ‘in the phenomenal context of demonstration, the relationship of agreement must become visible’.30 The point is not that what is interesting about demonstration is the mechanism of how the adaequatio of proposition and thing is confirmed or disconfirmed. Rather, it is that all such mechanisms – to whatever degree they might
25 SZ 214/257, italics removed.
27 Ibid.
28 SZ 217/259, 216/259.
29 SZ 216/259, italics removed.
30 SZ 217/260, italics removed; my italics on ‘demonstration’. Dahlstrom discusses this at length in the context of Heidegger’s appropriation of Husserl’s phenomenological account of truth and evidence (Heidegger’s Concept of Truth, chapter II).