When we turn to the consideration of time as infinitely divisible, we seem to find ourselves confronted with the same difficulties which presented themselves when we thought of space as infinitely divisible.  Certainly no man was immediately conscious of an infinite number of parts in the minute which just slipped by.  Shall he assert that it did, nevertheless, contain an infinite number of parts?  Then how did it succeed in passing? how did it even begin to pass away?  It is infinitely divisible, that is, there is no end to the number of parts into which it may be divided; those parts and parts of parts are all successive, no two can pass at once, they must all do it in a certain order, one after the other.

Thus, something must pass first.  What can it be?  If that something has parts, is divisible, the whole of it cannot pass first.  It must itself pass bit by bit, as must the whole minute; and if it is infinitely divisible we have precisely the problem that we had at the outset.  Whatever passes first cannot, then, have parts.

Let us assume that it has no parts, and bid it Godspeed!  Has the minute begun?  Our minute is, by hypothesis, infinitely divisible; it is composed of parts, and those parts of other parts, and so on without end.  We cannot by subdivision come to any part which is itself not composed of smaller parts.  The partless thing that passed, then, is no part of the minute.  That is all still waiting at the gate, and no member of its troop can prove that it has a right to lead the rest.  In the same outer darkness is waiting the point on the line that misbehaved itself in the last chapter.

28.  THE PROBLEM OF PAST, PRESENT, AND FUTURE.—­It seems bad enough to have on our hands a minute which must pass away in successive bits, and to discover that no bit of it can possibly pass first.  But if we follow with approval the reflections of certain thinkers, we may find ourselves at such a pass that we would be glad to be able to prove that we may have on our hands a minute of any sort.  Men sometimes are so bold as to maintain that they know time to be infinite; would it not be well for them to prove first that they can know time at all?

The trouble is this; as was pointed out long ago by Saint Augustine (354-430) in his famous “Confessions,” [1] the parts of time are successive, and of the three divisions, past, present, and future, only one can be regarded as existing:  “Those two times, past and future, how can they be, when the past is not now, and the future is not yet?” The present is, it seems, the only existent; how long is the present?

“Even a single hour passes in fleeting moments; as much of it as has taken flight is past, what remains is future.  If we can comprehend any time that is divisible into no parts at all, or perhaps into the minutest parts of moments, this alone let us call present; yet this speeds so hurriedly from the future to the past that it does not endure even for a little space.  If it has duration, it is divided into a past and a future; but the present has no duration.