as we have seen, is that the reference this word contains to the ergon as what is complete or finished seems especially unsuited to expressing the being of what is necessarily and essentially incomplete.
With this preparation, Heidegger’s main argument can now be simply stated. That the complete should equal the being of the incomplete (WP3, 11; daß das Fertige gleich dem Sein des Unfertigen) is absurd. Imagine translating the definition of motion as follows: “The being-complete [and here we can reintroduce the word ἐντελέχεια] of what is incomplete insofar as it remains incomplete.” What could be more absurd? Therefore, the being of the ergon that is applied to motion in defining it as an energeia is not being-complete, but simply being-present.16 What the definition of motion is defining it as is not the completeness of dunamis as dunamis—an absurdity—but the presence of dunamis as dunamis.17 The introduction of the way of being of the ergon into the interpretation of the being of motion is possible, Heidegger says, only on the assumption that the way of being of the ergon is understood as being-present (Anwesendsein). It is by way of this argument that Heidegger can conclude that “Aristotle seeks, not another concept of being, but simply to clarify this conception in relation to what is in mo-tion and thus to a determinate region” (WP3, 11). In the published protocol, Heidegger makes perfectly clear just how important this conclusion is to him: “The assumption on which our entire interpretation depends is that energeia and being in general signify for Aristotle presence [Anwesen>heit]” (GA83, 254). The envisioned “breach in ancient ontology” threatened a breach in the interpretation of Aristotle, and indeed of the Greeks in general, that Heidegger had been developing for years. The breach, then, had to be closed.
To say that Heidegger needed his conclusion is not to say that he lacked a strong argument. Indeed, Heidegger’s argument can be seen as a challenge to which any serious reader of Aristotle must respond: is it possible to understand the definition of motion without understanding the key terms energeia and entelecheia as meaning “presence”? If we emphasize in the term entelecheia the idea of “possessing the end” and thus the sense of “completeness,” we have the seeming absurdity Heidegger notes of defining motion as the completeness of what remains incomplete. If we pursue another route Heidegger does not pursue here, that is, understanding energeia as being-at-work or being-active, then we have a definition that appears circular in defining motion as the activity or the being-active of what is dunaton as such.18 All depends on how we understand the distinction we have seen
16. In his own notes Heidegger writes: “Ἐνέργεια demnach nicht Fertigkeit, sondern Vorhandenheit, Antreffbarkeit” (GA83, 13).
17. In SS1924 Heidegger therefore claims that Aristotle is speaking more carefully when he uses the word energeia rather than entelecheia (Sich-in-seinem-Ende-Halten) in defining the being of motion (GA18, 321). However, he also notes there that there is a sense in which the dunamei on as such achieves its end or completeness in motion: “Das In-der-Möglichkeit-sein kommt in dem In-Arbeit-Sein zu seinem Ende, ist dann eigentlich was es ist, nämlich Seinkönnen” (321).
18. In his own notes, Heidegger does emphatically assert that energeia in the definition cannot mean “actus, Bewegtheit” (GA83, 12, 13).