Jeff Malpas on the entanglement of aletheia and physis.
In his later thinking, Heidegger will explore the concept of nature through the Greek "physis," exhibiting "physis" as standing in intimate relation to "aletheia" — nature, in this primordial sense, itself appears as a mode of the concealing/revealing of being. Thus Heidegger says in Basic Questions of Philosophy (from 1937—1938) that “The fundamental character of φύσις [physis] is ἀλήθεια [aletheia], and φύσις, if it is to be understood in the Greek sense and not misinterpreted by later modes of thought, must be determined on the basis of ἀλήθεια."
The way in which the various issues that come to light here connect to the question of world, transcendence, and the conceallng-unconcealing of truth is somewhat tangled, and, in the period of the late 1920s, and even into the early 1930s, is not yet clearly worked out in Heldegger’s thinking. Yet it should already be appurent that what emerges is a set of issues centered around the attempt, not only to think the happening of disclosedness, and so of world, in a way that would rule out any grounding of that happening in the human, but also to understand it in a way that encompasses the "mystery" of that happening, and so does not treat it merely as the happening of disclosedness, but also of that which is not disclosed, that which remains concealed or else appears as concealment.