Page - 471 - in The Complete Aristotle

neither movement nor independent of movement. We must take this as our starting-point and try to discover-since we wish to know what time is-what exactly it has to do with movement. Now we perceive movement and time together: for even when it is dark and we are not being affected through the body, if any movement takes place in the mind we at once suppose that some time also has elapsed; and not only that but also, when some time is thought to have passed, some movement also along with it seems to have taken place. Hence time is either movement or something that belongs to movement. Since then it is not movement, it must be the other. But what is moved is moved from something to something, and all magnitude is continuous. Therefore the movement goes with the magnitude. Because the magnitude is continuous, the movement too must be continuous, and if the movement, then the time; for the time that has passed is always thought to be in proportion to the movement. The distinction of ‘before’ and ‘after’ holds primarily, then, in place; and there in virtue of relative position. Since then ‘before’ and ‘after’ hold in magnitude, they must hold also in movement, these corresponding to those. But also in time the distinction of ‘before’ and ‘after’ must hold, for time and movement always correspond with each other. The ‘before’ and ‘after’ in motion is identical in substratum with motion yet differs from it in definition, and is not identical with motion. But we apprehend time only when we have marked motion, marking it by ‘before’ and ‘after’; and it is only when we have perceived ‘before’ and ‘after’ in motion that we say that time has elapsed. Now we mark them by judging that A and B are different, and that some third thing is intermediate to them. When we think of the extremes as different from the middle and the mind pronounces that the ‘nows’ are two, one before and one after, it is then that we say that there is time, and this that we say is time. For what is bounded by the ‘now’ is thought to be time-we may assume this. When, therefore, we perceive the ‘now’ one, and neither as before and after in a motion nor as an identity but in relation to a ‘before’ and an ‘after’, no time is thought to have elapsed, because there has been no motion either. On the other hand, when we do perceive a ‘before’ and an ‘after’, then we say that there is time. For time is just this-number of motion in respect of ‘before’ and ‘after’. Hence time is not movement, but only movement in so far as it admits of enumeration. A proof of this: we discriminate the more or the less by number, but more or less movement by time. Time then is a kind of number. (Number, 471