have an adequate concept of the soul or the understanding—of the Dasein—it remains difficult to say what "time is in the soul" means. Nothing is gained by saying that time is subjective; at most, it would give rise to problems put precisely the wrong way.
The question now arises. How can different entities and different moving things which are in time be in or at the same time if they are different? How is the simultaneity of different things possible? We know that the question about simultaneity or, more precisely, the question of the possibility of an intersubjective establishment of simultaneous events constitutes one of the basic problems of relativity theory. The philosophical treatment of the problem of simultaneity. depends on two factors: (1) determination of the concept of intratemporality, the question how something is in time at all, and (2) clarification of the question in what way and where time is or, more precisely. whether time in general is and can be said to be.
Since time for Aristotle is something connected with motion and is measured by means of motion, the problem is to find the purest motion, which is the original measure of time. The first and pre-eminent measure of all motion is the rotation (κυκλοφορία) of the outermost heaven. This motion is a circular motion. Time is thus in a certain sense a circle.
From this brief survey it already appears that Aristotle broached a series of central problems relating to time. and in fact not indiscriminately but in their essential concatenation. Nevertheless, it should be noted that many problems are just touched on by him and also that those with which he deals more circumstantially are by no means without need of further inquiry and new radical formulation as problems. Seen in their entirety, however, all the central problems of time which were thereafter discussed in the course of the further development of philosophy are already marked out. It can be said that. subsequent times did not get essentially beyond the stage of Aristotle's treatment of the problem—apart from a few exceptions in Augustine and Kant, who nevertheless retain in principle the Aristotelian concept of time.
Following this survey of Aristotle's essay on time we shall try to gain a more thorough understanding of it. In doing so. we shall not keep strictly to the text but, by a free discussion and occasionally by carrying the interpretation somewhat further. we shall try to focus more clearly on the phenomenon as Aristotle sees it. We start here from the definition of time already adduced: τοῦτο γάρ ἐστιν ὁ χρόνος, ἀριθμὸς κινήσεως κατὰ τὸ πρότερον καὶ ὕστερον14 for time is just this, something counted in connection with
14. Aristotle, Physica, 219b 1.