Enneads III.7: Of Time and Eternity
Nor Can Time Be a Numbered Number (As Aristotle Claimed[452])
What is this number? Is it composed of unities? How does it measure? That would still have to be explained. Now let us suppose that we had discovered how it measures; we would still not have discovered the time that measures, but a time that was such or such an amount. Now that is not the same thing as time; there is a difference between time and some particular quantity of time. Before asserting that time has such or such a quantity, we have to discover the nature of that which has that quantity. We may grant that time is the number which measures movement, while remaining exterior thereto, as "ten" is in "ten horses" without being conceived with them (as Aristotle claimed, that it was not a numbering, but a numbered number). But in this case, we still have to discover the nature of this number that, before numbering, is what it is, as would be "ten" considered in itself.[454] It may be said that it is that number which, by following number, measures according to the priority and posteriority of that movement.[452] Nor do we yet perceive the nature of that number which measures by priority and posteriority. In any case, whatever measures by priority or posteriority, or by a present moment,[455] or by anything else, certainly does measure according to time. Thus this number (?) which measures movement according to priority or posteriority, must touch time, and, to measure movement, be related thereto. Prior and posterior necessarily designate either different parts of space, as for instance the beginning of a stadium, or parts of time. What is called priority is time that ends with the present; what is called posteriority, is the time that begins at the present. Time therefore is something different from the number that measures movement according to priority or posteriority,--I do not say, any kind of movement, but still regular movement. Besides, why should we have time by applying number either to what measures, or to what is measured? For in this case these two may be identical. If movement exist along with the priority and posteriority which relate thereto, why will we not have time without number? This would amount to saying that extension has such a quantity only in case of the existence of somebody who recognizes that it possesses that quantity. Since (Aristotle[456]) says that time is infinite, and that it is such effectually, how can it contain number without our taking a portion of time to measure it? From that would result that time existed before it was measured. But why could time not exist before the existence of a soul to measure it? (Aristotle)
might have answered that it was begotten by the soul. The mere fact that the soul measures time need not necessarily imply that the soul produced the time; time, along with its suitable quantity, would exist even if nobody measured it. If however it be said that it is the soul that makes use of extension to measure time, we will answer that this is of no importance to determine the notion of time.
POLEMIC AGAINST EPICURUS: TIME IS NOT AN ACCIDENT OR CONSEQUENCE OF MOVEMENT.
9. (10). When (Epicurus[457]) says that time is a consequence of movement, he is not explaining the nature of time; this would demand a preliminary definition of the consequence of movement. Besides, this alleged consequence of movement--granting the possibility of such a consequence--must be prior, simultaneous, or posterior. For, in whatever way we conceive of it, it is within time. Consequently, if the consequence of movement be time, the result would be that time is a consequence of movement in time (which is nonsense).
PLOTINOS CAN GO NO FURTHER IN REFUTING ENDLESS DEFINITIONS OF TIME.
Now, as our purpose is to discover, not what time is not, but what it really is, we notice that this question has been treated at great length by many thinkers before us; and if we were to undertake to consider all existing opinions on the subject, we would be obliged to write a veritable history of the subject. We have here, however, gone to the limit of our ability in treating it without specializing in it. As has been seen, it is easy enough to refute the opinion that time is the measure of the movement of the universe, and to raise against this opinion the objections that we have raised against the definition of time as the measure of movement in general, opposing thereto the irregularity of movement, and the other points from which suitable arguments may be drawn. We are therefore free to devote ourselves to an explanation of what time really is.