Augustine was particularly enamored with the concepts of memory and time. A poem stored up in a man’s memory has no temporal extension; it moves dimensionally into the present as syllables are sounded out. And no sooner has it moved into the present then it is stored back into the past.
One might argue as Vladimir Nabokov did through Humbert Humbert. Humbert described his own self awareness as “a continual spanning of two points, the storable future and the stored past.”
Gary Wills quotes Nabokov in his book on St. Augustine, and states that “time is a shuttling of the future in to the past, moving through in a measurable point.” St. Augustine said, “If we could suppose some particle of time, which could be divided into a smaller particle, that alone deserves to be called the present, yet it is snatched from the future and flits into the past without any slightest time of its own. If it lasted, it could be divided into part-future and part-past. So there is no ‘present’ as such.” (T 11.20)
Augustine is right, but we can only think of the past while in the present – so that time may have its “present tense,” but it never has its rest.
We err when we try to conceive of the present tense as time at rest. The present is gone before we perceive it. So that as the present passes, we then use our present-tense memory of the moment just past to contemplate a supposed state that we call the present.
I think our concept of present is essentially a collection of immediate past moments. This is not to say there is no present whatsoever.
It is to say that the present as we conceive of it exemplifies a duration that is longer than the present can be. I think our perception of the present feels as if time were at rest.
We hold on to the immediate collection of past moments as if they add up to the present. But despite Augustine’s contention on the line of time, if there is past and if there is future, then any distinct point on that line must be “passed through.” If I am at that distinct point, then the “passing through” is my present.