Mead thinks that each emerging moment changes the past. It’s difficult to see how it could be otherwise.

This doesn’t mean that the directionality of the past is an illusion or reversible. Things done cannot be undone. But what those things are and mean changes as time moves along. The past, not just our view of it, changes over time.

Start with Augustine.

Augustine pointed out that we have no simple “past” but only the “present of the past” (the past preserved in memory and memorializations of various sorts, including writing) no future but only the “present of the future.” As the present changes, we have a different “present” in the “present of the past,” and that implies we’ve got a different “present-past” combination. Since this is the only past we have, the past must change with the changing present.

One might say that we have a fixed past but changing present perspectives on that past. One might say that, but it would be a waste of air. For two reasons: First, because saying that the past is fixed turns it into something other than time, since time isn’t fixed; second, because even if it were true that the past is fixed and we only have different views of it, we could never know.

We can never escape the present and get into the past in its purity. If we could - by a time machine, say - it’s questionable whether it would still be past to us. Characters in time travel stories usually know they’re in the past, but they can know that only if they have memories that reach into their present. If we truly traveled back in time, what is now past to us would be present. Aside from those fantasies, we have only the “present of the past,” and no “pure past” with which to compare it, and hence no knowledge of a fixed past against which we can measure our “present-past.” A hypothetical fixed past, even if real, is irrelevant.

Two clarifications: First, the problem this raises is the problem of defining “the present.” If, as is usually assumed, the present is the narrow crest of the wave of time, the past is shifting every moment. But Rosenstock-Huessy has argued persuasively that this is too narrow a view of what constitutes present. The present is socially and politically articulated, and can be anything from a moment to a concert to an epoch.

Second, Mead’s suggestion that this line of argument seems to open up vertiginous abysses. If the past isn’t fixed, how can time be stabilized? How can we avoid purely relative time? But those questions are either nonsensical or unbelieving. Nonsensical because time, by definition, isn’t stabilized or stabilizable, and, as noted above, the desire to fix the past as an anchor for the present denies the temporality of the past. Time is not a lava flow, which hardens as soon as it passes through the present. Unbelieving because, of course, time is relative to the Personal Absolute who is the Triune God. (Or, perhaps, our time is relative to the absolute time that is God’s Triune uncreated temporality and rhythmicity. Or, perhaps, relative/absolute are the wrong terms, since our time is only insofar as it receives itself as a gift from God and shares in the one in whom we live and move and have our being.)