What then is time? Provided that no one asks me, I know. If I want to explain it to an inquirer, I do not know. But I confidently affirm myself to know that if nothing passes away, there is no past time, and if nothing arrives, there is no future time, and if nothing existed there would be no present time. Take the two tenses, past and future. How can they ‘be’ when the past is not now present and the future is not yet present? Yet if the present were always present, it would not pass into the past: it would not be time but eternity. If then, in order to be time at all, the present is so made that it passes into the past, how can we say that this present also ‘is’? The cause of its being is that it will cease to be. So indeed we cannot truly say that time exists except in the sense that it tends towards non-existence.
Ultimately, he can do little more than clarify his terminology, anticipating Wittgenstein by concentrating more on how the terms are used than on what they mean or are:
What has interested me the most is the extent to which our increasing knowledge of the physical brain has turned out to align nicely with Augustine's metaphysical soul-concept. The "present of things past" anticipated that engram that Lashley invested so much of his life in trying to find without success, although within the last ten years in appears that Richard Thompson and his colleagues at USC have managed to associate it with a localized region in the cerebellum. Meanwhile, we have Gerald Edelman to thank for demonstrating that the "present of things present" is actually a "remembered" present. New BBC NEWS has reported results from Washington University concerning the "present of things to come," presenting evidence that this, too, is localized, in this case in the left lateral premotor cortex, the left precuneus and the right posterior cerebellum. It is nice finally to home in on some good news at the start of a year that began with so many ill omens!
What is by now evident and clear is that neither future nor past exists, and it is inexact language to speak of three times—past, present, and future. Perhaps it would be exact to say: there are three times, a present of things past, a present of things present, a present of things to come. In the soul there are these three aspects of time, and I do not see them anywhere else. The present considering the past is the memory, the present considering the present is immediate awareness, the present considering the future is expectation.