D. Response to the Instance

138. But this reason is not valid, because ‘something’s being in time is like something’s being in number’ [Physics 4.4.12.221a17-18], but it is not of the idea of a being existing in number that it be exceeded by number - rather, if the first numbered thing is taken (that is, the adequate one), it is equal to number itself; but it is of the idea of the first numbered thing that a part of it is exceeded by number, because the whole is greater than its part and the whole is equal to the number; therefore part of it is exceeded by number.

139. Therefore I say about an entity in time that, from the fact any such entity is of necessity variable according to its varying being, it must be that in accord with something of itself - namely in accord with some discreteness which it has on the part of time - it is exceeded by time, because it will be disposed differently in a different part of time; and for this reason it is that impossible and necessary things ‘are not in time’ [n.137], because there is no difference of disposition in them so that they could be exceeded by time or be differently disposed. But the first motion, although not in its totality exceeded by time, yet is exceeded by time as to some part of itself, and this suffices for it to be truly said to be measured by time; and it seems unacceptable that time, since it is a uniform measure, should not have some first uniform measured thing.

140. And then to the argument [n.136]:

I deny the consequence [sc. if the first angel is not measured by aeviternity, then the first motion is not measured by time], because the reason is not the same here as there. For if the first motion is measured by time, this is either because motion is posited to be something other than time (because of the reason set down above, from the Physics, n.85), or because, by positing time to be the same as motion, that motion can measure itself (not indeed first, but it measures the whole by the part of it that is known, as the Philosopher says in Physics 4.12.220b32-1a4, “Time measures motion itself by determining some motion that will afterwards measure the whole motion, as a cubit measures length by determining some length that will measure the whole”); but neither reason is found in the issue at hand, because there is not anything in the first aeviternal thing other than its existence, nor is its own very existence an extension, or a quantum, that could measure itself by some known part of itself [n.122].