that those beings that are by φύσις, whether all of them or some of them [those not in rest], are moving beings (i.e., determined by movedness)” (WBP 313). Indeed, Aristotle maintains that the problem of movement was the stumbling block in the attempt of his predecessors to think about being. In this quote, Aristotle seems to be saying that he will simply take it for granted that the philosophical question is the question of κίνησις. But the opposite is the case. Unlike his predecessors, whom Aristotle accuses of having lazily neglected the question of movement,6 Aristotle promises to devote the most strenuous philosophical effort to place the question of movement at the center of his thought, and to view it as the most fundamental question when addressing the question of being. Heidegger says that Aristotle was the first to raise the issue of movement to a philosophical level.
Heidegger cautions us about a basic confusion at the heart of this issue. It is not the particular motion from place to place that is under investigation, but rather how such beings that have the power to move of themselves are. For these beings to be, movement must belong to their very way of being. The fact that these beings at any given time may be at rest does not mitigate the fact that movement must characterize their way of being. The opposition of motion and rest has its origin in this movedness or being-moved. Rest is not the negation of being-moved. Rather it is the concentrated and fulfilled expression of this way of being. In the history of metaphysics, there is a tendency to exclude motion from being and to understand motion as nonbeing. Thus, the eternal and permanent are held to be more being than the changing and finite. In such a framework, the question of movement, the being of κίνησις, being in the sense of movement, gets bypassed.
The fundamental question of κίνησις is not a question about the behavior of beings. To use Heideggerian terms, the Physics is not an ontic inquiry, but an ontological inquiry. In Book A of the Physics, Aristotle says that had his predecessors seen this φύσις, they would not have turned away from coming to be and change, and their ignorance would have been dispelled.7 Moreover, he says, this φύσις, this being-moved, does not violate the fundamental premise about being—namely, that being either is or is not. Actually, Physics A 8 is quite pronounced on this issue. It is about how the law of non-contradiction, that being and nonbeing cannot both be at the same time, does not preclude the reality of natural beings that come to be and whose being is co-constituted by privation (191 b26–192 a27). The aporia, he says, that befuddled his predecessors regarding the existence
6. Aristotle, Metaphysics 985b19.
7. Aristotle, Physics 191 b30–35.