In Book 11 of the Confessions, Augustine writes, “Are the present hundred years a long time? But first see whether a hundred years can be present. If it is the first year of the hundred, then that year is present, but the other ninety-nine are still in the future, and so as yet are not; if we are in the second year, then one year is past, one year is present, the rest future. Thus whichever year of our hundred-year period we choose as present, those before it have passed away, those after it are still to come. Thus a hundred years cannot be present.”
Is the chosen year itself present? Not wholly: We’re in some particular month, and the other months are not present. And so on — Augustine applies the same argument to days, hours, and even “fleeting moments.” In the end, “If we conceive of some point of time which cannot be divided even into the minutest parts of moments, that is the only point that can be called present: and that point flees at such lightning speed from being future to being past, that it has no extent of duration at all. For if it were so extended, it would be divisible into past and future: the present has no length.”