At no time then hadst Thou not made any thing, because time itself Thou madest.
And no times are coeternal with Thee, because Thou abidest; but if they abode, they should not be times.
For what is time?
Who can readily and briefly explain this?
Who can even in thought comprehend it, so as to utter a word about it?
But what in discourse do we mention more familiarly and knowingly, than time?
And, we understand, when we speak of it; we understand also, when we hear it spoken of by another.
What then is time?
If no one asks me, I know: if I wish to explain it to one that asketh, I know not: yet I say boldly that I know, that if nothing passed away, time past were not; and if nothing were coming, a time to come were not; and if nothing were, time present were not. Those two times then, past and to come, how are they, seeing the past now is not, and that to come is not yet?
But the present, should it always be present, and never pass into time past, verily it should not be time, but eternity.
If time present (if it is to be time) only cometh into existence, because it passeth into time past, how can we say that either this is, whose cause of being is, that it shall not be; so, namely, that we cannot truly say that time is, but because it is tending not to be?
Confessions of Saint Augustine
Chapter XIV
