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There’s No Time like the Present
University of York
Centre for Philosophy of Time, University of Milan
Time passes, time passes. Things change from moment to moment. Events in the future are far off and distant, to begin with, but they gradually approach the present. Some future events, such as the end of term here in York, are not too distant. (My students breathe a sigh of relief.) The end of term approaches, it will become present, and then it recedes into the past. This is a perfectly natural way of thinking about time, a way of thinking that should be captured by our best models of time. It’s unhelpfully metaphorical, to be sure, but there’s something deeply significant about the metaphor; something about genuine becoming, genuine change, that should be preserved.
With that in mind, here’s the model that I think does the best job of capturing that metaphor: only present things exist and what’s present really changes. Write down a list of absolutely everything that exists and there won’t be a single past or future item on the list. No dinosaurs, no Roman Emperors, no Martian colonies, nor hover cars. But, of course, this list isn’t set in stone. It’s constantly changing. Things begin to exist, and cease to exist, as time passes. (Dinosaurs existed, although they exist no more.) Reality isn’t static, it’s dynamic. And the present is special: there’s really no time like the present. There are, really, no other times at all. This seems to me to be a pretty “common sense” way of thinking about time and passage. And, by asserting that only what’s present exists, absolutely, I endorse a view about time called ‘presentism’.
Presentism is a model of the nature of reality. Philosophers of time are in the business of developing such models. But not all agree with my assessment that the “common sense” way of thinking is correct. (I suspect that more than most would agree that it’s the natural way to think about time, but they think that it’s just not the way things really are.) Here’s one key point on which we diverge: unlike some of my opponents, I think that there’s an important (and objective) difference between what’s present and what’s wholly past or future. And, crucially, I think that one major way that this difference manifests itself is in terms of what exists: there are no wholly past or future things whatsoever.
So, take some wholly past entity, such as Boudica, the Queen of the Iceni, who died almost 2,000 years ago. I say that she doesn’t exist at all. Boudica existed, to be sure, she was present—but she exists no longer. This is real temporal change: a kind of change that’s expressible in terms of what exists absolutely, and the kind of change that’s at the heart of the ordinary way of thinking about the passage of time. What has existed is no more. As I said above, this is how I think that we should think of time passing.
But all of this prompts a question: if what has existed—what’s wholly ‘in the past’—doesn’t exist at all, then how do we get to talk about the past? How do I get to refer to Boudica, if there’s literally nothing there for me to refer to? How do I get to talk truthfully about Boudica, if there’s nothing that exists to explain why what I say is true? Well, I say that Boudica doesn’t exist, but she existed and she has left her mark on the world. (Quite literally, in fact.) When something ceases to exist, when something goes out of existence, something else is left behind. There’s genuine change—Boudica exists one moment, and then doesn’t exist at all the next—but she doesn’t vanish without a trace.
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A trace of the past exists now. More accurately, traces of the past exist now and will continue to exist. When Boudica existed, she had a special kind a property, a property that only she could ever have, something essential to her: the property of being identical with Boudica. Here’s the twist: I say that this property continues to exist even after some time has passed and Boudica has ceased to be present. This property is the mark that Boudica leaves upon the world. (And this goes for all things that have existed but exist no longer.) Accepting such properties, such ‘traces of the past’, allows presentists to refer to past things and to talk truthfully about them. When we aim to talk about the past, what we actually talk about are these present traces. For any object whatsoever, that existed but exists no more, it has left behind its essence, its mark upon the world. Time passes, and objects come and go, but their essences remain as real traces of the unreal past.