The main thesis of this essay is that the basic phenomenon of truth (aletheia), 'the openness of the world' could be crucial for the concept of 'state of affairs' (Bewandtnis) identified with a set of practical and intersubjective rules of actions. Truth is to be identified with implicit and pre-conceptual 'knowledge-how' rather than an explicit '‘knowledge-that' articulated in theoretical statements. If such practical understanding of environment offers the only and basic access to the world, and if it simultaneously discloses meaningful entities (tools) for theoretical thinking, the idea of a theory being true, understood as being adequate or correspondent to the world, becomes quite problematic. In fact, the relation of correspondence implies a comparison of statements about present entities with practical action-rules. Since alternative articulations of the world in the terms of 'handiness' on the one hand, and 'presence' on the other, belong to two reciprocally irreducible and incomparable conceptual systems (what corresponds to eg. Quine's distinction between the 'mental' and the 'physical'), Heidegger's 'early' philosophy points to the necessity of distinguishing between a practical context of discovery and theoretical context of justification.