Being in Aristotle

coming-into-appearance in such unfolding, and holding itself and persisting in appearance.21

We note two distinct meanings of ϕύσις here, one referring to things, the other referring to the being of those things. In the beginning of Greek philosophy, Heidegger says, ϕύσις in one sense was a name for things, indeed all things, whether they are natural things or artifacts; and in a second sense, ϕύσις is not a thing but is that which allows all those things to emerge as what and how they are. Heidegger also points out the etymological connection between the Greek ϕυ- and ϕα-, which are the respective roots of ϕύειν and ϕαίνεσϑαι (“to grow” and “to show”), which in turn are the etymons of ϕύσις (the unfolding-emergence of a thing into visibility and availability) and ϕαινόμενον (that which has unfolded and emerged and so is visible and available). Note that the following two texts are referring to the self-showing (or intrinsic availability) of things, but not of ϕύσις in its second sense, as the being of things.

Recently, the radical ϕυ- has been connected with ϕα-, ϕαίνεσϑαι. Φύσις would then be something that emerges into the light; ϕύειν: to light up, to shine forth, and therefore to appear.22

The roots ϕυ- and ϕα- name the same thing. Φύειν—the emerging [of a thing], an emerging that reposes in itself—is ϕαίνεσϑαι, being lit up, showing up, appearing.23

In other words, ϕύσις does what ἀλήϑεια does:

it makes something manifest. This already implies that the being [of something], i.e., its appearing, is letting-that-thing-step-forth from hiddenness. Insofar as a thing as such is, it is placed into and stands in disclosedness, ἀλήϑεια.24

It is important to be clear on this point: Such unfolding, emerging, and appearing is that of a thing and not of ϕύσις itself. In the origins of Western

21. GA 40: 15.25–28 and 16.23–26 = 15.1–4 and 15.28–32; see ibid., 134.5–6 = 138.14–15: “das aufgehende Walten.” GA 66: 87.2–3 = 72.28–29: “Im ersten Anfang: der Aufgang (ϕύσις), die sich entfaltende (öffnende) Anwesung.”
22. GA 40: 76.13–16 = 78.19–22: “das ins Licht Aufgehende”; leuchten, scheinen, erscheinen. See Friedrich Specht, “Beiträge zur griechischen Grammatik,” 61.35–62.4. “Such an active φαύειν [= φάειν, to shine] would have to coincide in meaning with ϕύειν and thus be a kind of causative verb to ϕύεσθαι [i.e., to make something come forth].” Fried and Polt provide a helpful reference to this article at p. 78, note 14, of their translation of GA 40.
23. GA 40: 108.9–11 = 110.20–22: “das in sich ruhende Aufgehen.”
24. GA 40: 109.15–18 = 112.3–5; see 147.21–22 = 154.17–18: “Sein besagt: im Licht stehen, erscheinen in die Unverborgenheit treten.” All of these verbs name what an entity does thanks to its being-qua-ϕύσις.