mode of being of natural beings leads Aristotle to confirm the legitimate ontological status, and indeed the participation in Being of non- presence.
It should be noted that, for anyone who knows Aristotle fairly well, Heidegger’s understanding of κίνησις as the mode of being of natural beings faces some heavy resistance. In Physics book III, Aristotle takes up the task of giving an account of κίνησις, having observed that, according to all of his predecessors save Parmenides, motion or change seem to be a fundamental feature of the natural world, which it is after all the task of the Physics to explain and make intelligible. This presents a problem because motion or change seems to be “something indefinite, and a host of negative principles [such as otherness, non-identity, and non-being] seem also to be indefinite, since none of them is a ‘this [tode]’ or a quality, nor do they belong to any of the other ways of attributing being” (Phys. III.201b24–27). The natural world, then, threatens to become a sea of unintelligible alteration, approaching simple non- being, which is precisely what drove Plato to posit the Ideas above and beyond the apparent Heraclitean flux of the natural world and grant these Ideas alone true Being and intelligibility. Aristotle, by contrast, declares that although κίνησις is indeed in a sense “indefinite,” it is nonetheless intelligible as a certain play of δύναμις and ἐνέργεια, a certain dynamic according to which natural beings are what they are by actualizing their potency to be.
However, this then requires Aristotle to distinguish two different ways in which potency is actualized, for in both the process by which a thing changes or comes-to-be and in that thing’s just persisting, being the thing it is, Aristotle sees the actualization of a potency. Consider the stones that will be used to construct a temple, for instance. Those stones have the potential to undergo the process of construction—they can become otherwise, be moved and carved and assembled, ultimately taking on the form of a temple. This is κίνησις, change or motion, and Aristotle famously declares, “the actualization of a being in potency, as potency, is κίνησις [ἡ δυνάμει ὄντος ἐντελέχεια, ᾗ τοιοῦτον, κίνησίς ἐστιν]” (Phys. III.201a10–11). However, once the temple is constructed, as it stands there on the hilltop, simply being a temple, this too is the actualization of its material’s potency, not its potency as potency or its potency to change and become other than it is, but its potency to be a temple. Thus, both in changing or coming to be and in being, Aristotle finds the ἐνέργεια of δύναμις, the actualization or more literally the “putting to work” of a potency, but in explicitly different ways. In order to capture this distinction, Aristotle ultimately declares that, as opposed to εἶναι or “being,” “κίνησις seems to be some sort of ἐνέργεια, but an incomplete one [ἀτελές]” (Phys. III.202a32–33).