physis

is a loosely organized power of clans organized around [mediating, timely] heroes, who like the Gods whoosh up at crucial moments and then subside.

Presumably. . . a loosely organized power of clans organized around heroes, who like the gods whoosh up at crucial moments and then subside' (Dreyfus 'being and power' NET).

is not simply 'nature,' but, in a way that is truer to the greek experience of the world than the latin term, it means 'the sprouting and emerging of being from concealment'.

The Greek word physis means 'nature,' and hence physics is the study of nature. But the English/German word 'nature/Natur' comes from a Latin root, natura, and Heidegger is no admirer of the Latin language. He sees the translation of Greek philosophical terms into Latin as a grievous process through which the Greek experience of the world is trivialized, giving a hollow and self-evident ring to the mysteries of ancient Greek Dasein. For Heidegger, physis is not simply 'nature,' but the sprouting and emerging of being from concealment.

is the substance of things which have in themselves as such a source of movement.

Aristotle defines physis as 'the substance of things which have in themselves as such a source of movement' (Metaphysics, 1015a13-15).

physis, n.All

physis