their opposites.13 Take perhaps the most promising candidate: otherness. As Weiss notes, the mere fact of A being other than B does not produce any motion or transition between them. Heidegger refers at this point to Simplicius’s later interpretation of heterotês (otherness) as heteroiôsis,14 “othering” or becoming-other (Anderswerden), and notes that this latter concept does hit upon the phenomenon of motion.15 “Being-other” is a purely formal category, whereas “becoming-other” is the concrete phenomenon. The class ends by adding to this distinction another between heteroiôsis, translated as Änderung, and alloiôsis, translated as Veränderung: the difference is that in the latter case, but not in the former, something identical remains throughout the change. The example given of the former is a color changing, whereas the example given of the latter is a person changing. Though this is not said in either set of notes, this distinction appears to correspond to the first two senses of hupokeimenon noted earlier.
The next class of July 9 is of great importance since here, after the questions and doubts of the previous classes, Heidegger defends forcefully and at length the thesis that Aristotle’s definition of motion does not after all represent a new conception of being, but simply applies to motion, and the things of nature characterized by motion, the traditional conception of being as presence. If the text earlier suggested a “breach in ancient ontology,” Heidegger now firmly and completely closes the breach. In making his argument, Heidegger significantly focuses on the characterization of motion as an energeia, rather than its characterization as an entelecheia. He connects the former term to the term ergon, the finished product, what is complete (Fertigsein). Aristotle’s definition of motion thus defines it as the being-in-ergon, that is, the being-finished, the being-complete of the dunamei on qua dunaton. But what does this mean? The dunaton that is in motion qua dunaton is precisely as such and always incomplete, unfinished. To emphasize this point, Heidegger begins the class with discussion of why Aristotle’s predecessors characterized motion as not-being and of the extent to which they were justified in doing so. What is in motion is at each moment other than it was; it is there and also not there (WP3, 9). It is precisely this indeterminacy of motion, recognized, as we have seen, by Aristotle himself when he describes motion as appearing aoriston, that Aristotle tries to capture with the notion of dunamis (WP3, 9). Motion is what occurs (sich ereignet) when a dunamis, a certain aptitude or capability, announces itself as such. But the question is: what kind of being does a dunamis have in thus announcing itself? Aristotle uses the word energeia. But the problem,
13. Cf. GA18, 319–320.
14. Simplicius 1882, 430ff.
15. Though providing, of course, only a circular definition that defines motion in terms of motion, as Heidegger notes in SS1924 (GA18, 318).