LECTURE 22 (222 b 16-223 a 15)

HOW CORRUPTION IS ATTRIBUTED TO TIME. ALL MOTION AND MUTATION IS IN TIME

             620. After the Philosopher has compared time and the 'now' to those things which are in time, he here clarifies certain things which were touched on above.

             First he shows how corruption is attributed to time. Secondly, where he says, 'These distinctions having been drawn . . .' (222 b 30), he shows how every motion and mutation is in time.

             Concerning the first part he makes two points. First he shows his position with an argument, and secondly with an example, where he says, 'A sufficient evidence . . .' (222 b 22).

             621. He says, therefore, first that every mutation, by its very nature [ratio], removes the thing which is changed from its natural disposition. But both generation and corruption occur in time. Therefore some have attributed the generation of things, like learning and such things, to time. They say that time is most wise because the generation of science occurs in time. But a certain philosopher named Paron, of the Pythagorean sect, held the contrary, namely, time is most unlearned since forgetfulness occurs because of the passage of time. And in this matter he spoke more correctly because, as was said above, time itself is the cause of corruption rather than of generation. This is so because time is the number of motion, and mutation in itself is destructive and corruptive. It is the cause of generation and existence only per accidens. For when a thing is moved, it recedes from a disposition which it formerly had. But that it should acquire a disposition is not due to the nature [ratio] of motion insofar as it is motion, but insofar as it is finite and completed. Motion has this perfection from the intention of the agent which moves a thing to a determinate end. Therefore corruption can be attributed rather to mutation and time; but generation and existence is attributed to the agent and the generator.

             622. Next where he says, 'A sufficient evidence . . .' (222 b 22), he shows the same thing by means of an example. He says that an adequate example of what has been said is that nothing comes to be unless there appears to be an agent moving it. But a thing can be corrupted even when that which moves it to corruption is not clearly apparent. Such corruption we customarily attribute to time, as when someone dies of old age because of a non-apparent, intrinsic, corrupting cause. But when someone is killed with a sword, his corruption is not attributed to time. In generation the generator is always manifest, because nothing is generated by itself. Therefore, generation is not attributed to time, as is corruption. Nevertheless, corruption is not attributed to time in the sense that time causes it, but because it occurs in time and the corrupter is not apparent.

             Finally where he says, 'We have stated, then . . .' (222 b 27), he concludes that he has discussed the following points: that time is; what it is; the meanings of 'now'; and the meanings of 'then', 'lately', 'just now', 'long ago', and 'suddenly'.

             623. Next where he says, 'These distinctions having been drawn . . .' (222 b 30), he shows with two arguments that all mutation is in time.

             The first argument is as follows. Faster and slower are found in every mutation. But these things are determined by time. For that is said to be moved faster which arrives first at a designated terminus in the same space. Moreover, there must be the same rule for each motion; for example, in local motion each motion must be either circular motion or motion in a straight line. For if one is a circular motion and the other is a motion in a straight line, then one is not moved faster because it arrives first at the terminus. And this must be understood in a similar way for the other genera of mutation. Therefore it follows that all mutation is in time.

             624. He gives the second argument where he says, 'But what is before . . .' (223 a 5). In this proof he uses the following proposition: before and after are in time.

             This is clear as follows. A thing is said to be before and after because of its distance from the 'now', which is the terminus of the past and the future. But these 'nows' are in time. Therefore both before and after are in time, for it is necessary that a 'now' and a distance from that 'now' be in the same thing. Likewise a point and a distance taken in respect to that point are in the same thing, for they are both in a line.

             Since he has said that before and after are determined by their distance from the 'now', he shows how this is found in the past and in the future conversely. In the past that is said to be before which is more removed from the 'now', and the after is closer to it. But in the future it is just the opposite. Therefore, if before and after are in time, and if before and after follow upon all motion, it must be that all motion is in time.