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Time, Identity & Free Will

The Metaphysics of Groundhog Day

Lawrence Crocker says it’s about time, and personal identity, and free will.

The 1993 movie Groundhog Day was, of course, made as an exploration of the metaphysics of time. The basic idea is that for on-location TV weatherman Phil Connors, the same Groundhog Day, February 2, in Punxsutawney keeps repeating. Only Phil, played by Bill Murray, retains his memory of the day’s previous iterations. The loop appears to be universe-wide, and one that physicists would have no Phil-independent means of detecting.

It’s not the only movie featuring time loops. Like Groundhog Day, the movie Edge of Tomorrow (2014) has time loops with memories retained only by a single individual – in this case Tom Cruise’s character, who faces an uphill battle against space invaders. The 2016 Canadian film ARQ also has time loops with retained memories, but in this instance by more than one person. Their distance from the time loop generator explains (not very consistently) who retains and who does not retain memory. The 1998 German film Lola rennt (Run Lola Run) has only three time cycles. No one, however, seems to have a general memory of the prior loop or loops – although there are hints that both Lola and her boyfriend have bits of memory. In the third loop Lola deftly jumps over the dog that she tripped over in the second loop. A remark from her boyfriend in three also suggests some memory of one and two. It is easier to fit Lola into a Groundhog time model than it is to do so for Edge.

Palm Springs (2020) is the closest to Groundhog Day’s temporal metaphysics, and also its worthiest and funniest successor. Three characters openly accumulate memories across loops, one or perhaps two doing so undercover. Only the very last scene raises questions about the film’s temporal topology. Happy Death Day (2017) and Happy Death Day 2u (2019) also feature time loops, but ‘comic horror’ being a category mistake, à la Gilbert Ryle, I haven’t ventured into their local times.

Groundhog Day 1
Groundhog images © Columbia Pictures 1993

Time & Supertime

But here I want to concentrate on Groundhog Day. Is it offering a plausible and consistent metaphysical picture of time? What can we learn from it?

Phil’s memory of his multiple Groundhog Days (or ‘Day’) establishes a ‘supertime’, in which each Day can be seen as one of a sequence of Days. When a loop ends, to be followed in supertime by another Day, all of the previous loop’s causal chains simply come to an end, except those that affect Phil’s memory of them. Otherwise, the Day ends, and Groundhog Day begins again, with no consequences from the previous Day.

It’s clear that no two Days overlap in supertime. It is not so clear whether or not there is a gap in supertime between the end of one Day and the beginning of another. If your own memory is good, you’ll recall that in the movie, each Day, that is, each loop, begins on or just before 6am. We repeatedly see 5:59 on Phil’s alarm clock radio just before it wakes him up for the new Day. We also know that at least one loop ended sometime near 3:04 am, since we see 3:02, and there are about two minutes of dialogue after that. The simplest possibility is that Dayn continues until 5:59am, at which point, in supertime, Dayn+1 commences. But it is also possible that Dayn comes to an end at, say, 3:10, and there is no supertime between 3:10 of one Day and 5:59 of the next, so that things go directly from 3.10 to 5.59. Or perhaps supertime runs on with nothing happening in any local time until 5:59. Since by definition nothing is happening, no direct observation could distinguish among these different time regimes, if they even actually mean different things. It would be hasty, however, to follow verificationism into a conclusion that one or another of these ideas is meaningless because untestable. The physicists’ explanation for time that loops in this way – once they have one – might well make empty supertime either attractive or unattractive. Indirect evidence, together with theoretical considerations, may give answers where no direct tests are possible. Were it insisted that there can be but one real time – supported by some argument about the essential nature of time – then Phil’s experienced supertime would have to be regarded as the real time. All the events can be placed in it sequentially such that any Day loop misses but is joined up with all the other loops.

It could be maintained that it is not that there is a loop in time at all; rather there is a very strange phenomenon that repeatedly takes almost the entire universe (apart from Phil’s memory) back to some specific earlier state, the usual laws of causality notwithstanding. On this line of reasoning, there was only one Groundhog Day. All the other seeming Groundhog Days were in supertime really February 3, February 4, and so on; but no one but Phil remembers March or the months that followed it for many years – all of which were dead winter. Indeed, planetary positions would remain stuck revolving in one small area for that entire period, as would the motion of the entire universe. Transient astronomical events visible on Groundhog Day, such as supernovae and gamma ray bursts, many light years distant from us, would gather back together and pop up again day after day; and, of course, biological aging would also be on hold. The best course for Phil is to accept local times as well as the supertime as entirely real.

Note that if Phil’s producer Rita (Andie MacDowell) had had her own repeating Days, they need not be the same in number as Phil’s. Phil may have gone through thousands of Days, while Rita was blessed with only four, for instance. In this case, the local time of Phil’s Days would not combine in supertime into a single ordering with the local time of Rita’s Days. Absent such sharing, these hypothetical Days of Phil and Rita would be only ‘partially ordered’ with regard to each other in supertime.

You might be tempted to object that time could not possibly work like this. If there were a supertime, all events in it would have to be completely ordered, whether we could determine the order or not. For my part, I would urge restraint in projecting the limits of our imagination onto metaphysical reality.

A Multiverse Alternative

On the interpretation of Groundhog Day I’ve just offered, almost all the causal chains of the universe disappear into nothingness at the end of each Day, save on the last Day. We can avoid this great annihilation by positing branching universes. Each Day is in a different and distinct universe, with a past shared with the others but with its own future. In no two universes do Rita and cameraman Larry return to Pittsburgh telling the same story.

Multiverses of one kind or another turn up frequently in time travel fiction, sometimes explicitly, sometimes by implication. If I shoot my grandfather-counterpart in a different universe, my me-equivalent is not born in that universe; but that does not interfere with my own birth or my building a time (and trans-universe) machine in my own.

Multiverses in fiction tend to be much less tidy than the multiverse theory in quantum mechanics, according to which the universe branches at each quantum event. Phil greatly complicates matters. Presumably, in those worlds in which Phil makes it through the day alive, he does not then disappear and physically remove to a different universe. Movie interpretation should minimize gross violations of physical law in that sort of way. Better to take the Phil of Day2 to have gotten a memory transfusion from the Phil of Day1, and so on, leaving one Phil per universe – each one going on to his own particular future.

The multiverse interpretation of the movie carries more metaphysical baggage than does the time loop interpretation. It also has uncongenial consequences for the continuity of the protagonist: in some of the universes he dies a gruesome death. So I am going to restrict myself in what follows to thinking about time loops. For extra credit, however, I invite you to work through the multiverse interpretation for the next two issues the movie raises.

What Was Freely Chosen Had To Happen

Groundhog Day implies a thesis on determinism and free will. Some definitions will be helpful. I take a closed system to be deterministic if and only if from any complete description of that system at a specific time, physical laws could produce one and only one subsequent state of the system. The popular definition of determinism, in terms of ‘predictability in principle’ is best avoided, for the reason given by Richard Boyd in the journal Philosophy of Science for December 1972: not all functions are computable (computability provides our most rigorous understanding of what it is for something to be predictable). A God who is outside of time might directly see in one fell swoop everything that happens at all times, but that would hardly be a prediction. Moreover, he would know the future even in a wildly non-deterministic world. Even a God within time, if suitably infinite, might solve a non-recursive function by the simple expedient of checking, in an instant, the infinity of possible solutions. But this deus in machina predictability strains the idea of ‘in principle’ so far that it’s no longer interesting.

‘Free will’ is even harder to define. It must include at least what it is about human action that would, if it exists, underlie moral responsibility, blameworthiness, praiseworthiness, and moral dignity. It should also underlie our feelings that we control a large part of what we do. ‘Compatibilism’ is the position that there could be free will even if determinism were true, and ‘incompatibilism’ is the denial of this. A few incompatibilists are ‘hard determinists’, contending that determinism holds and that this rules out moral responsibility – so our feelings of freedom and responsibility are delusional. Social scientists often sound like hard determinists.

For the most part, determinism seems to reign in Groundhog Day. Apart from those events that Phil’s activities affect, directly or indirectly, everything takes place on each subsequent Day just as it did on the first.

Groundhog Day 2

But what about Phil’s actions themselves? There is no reason not to regard them as free in the way we usually take standard cases of human action to be free. We see Phil choosing different courses after deliberating on his failures in prior Days. We find him blameworthy, especially in early Days, and praiseworthy later on.

In all this there is a subliminal argument for compatibilism. Phil’s actions have those characteristics we regard as exhibiting free will, but human actions outside Phil’s causal cone are, apparently, determined, because they exactly repeat on each Day rerun. There is, however, no reason to believe the other people in Punxsutawney to be any different with respect to freedom and determinism than is Phil. So Rita, though her behavior is determined, is also free, in just the same way as Phil is. They both make choices according to their experience and reasoning. Phil’s different choices on different Days are not inconsistent with determinism, since he has different initial conditions when he comes to make the ‘same’ choice on a later day, having a memory of the way the prior Days worked out. What makes Phil behave differently on each Day is that he encounters each familiar event with a different mind. I conclude that the Groundhog Day universe shows what has been called a ‘soft determinism’ version of compatibilism: physical determinism plus free will.

Continuing to be the Same Person, or Not Quite

Up to this point, for the time loop interpretation I have referred to Phil and Rita as if there were no issue whether the Phil-look-alikes and Rita-look-alikes of different Days are in fact the selfsame Phil and Rita. It’s time to look deeper into the personal identity issues of the movie.

The most popular philosophical theories of personal identity have been versions of the ‘memory continuity’ theory of identity, associated with John Locke (1632-1704), and the ‘physical’ or ‘bodily continuity’ theory of identity, congenial to materialists. Either theory, suitably presented, makes strong appeal to common sense. Neither of them, however, give us entirely satisfying results for Groundhog Day.

Phil doesn’t seem to entertain the slightest doubt that he is the same person throughout. It’s not that he doesn’t go through some significant changes – for instance, learning piano and French, and over time, developing a worthier character. He might well want to say that he ‘had become a different person’ – but this is in the metaphorical way that we express significant differences in character residing in one and the same metaphysical person. Phil certainly believes on one Day that the pains and pleasures of the next Day will be his pains and pleasures, things to be avoided or sought, and anticipated with pleasure or apprehension. Remember his cross-Day campaign to seduce his ‘high school classmate’ Nancy Taylor.

As we watch the movie, we are drawn to the ideas that there is one self-identical Phil repeating and repeating Groundhog Day. We are not dissuaded from this view when Phil drives his car over the brink into a mine pit. The subsequent explosion and fire must have wreaked utter havoc on Phil’s body. At 5:59 on the next Day, however, there is Phil, or so we confidently accept. Phil and we, therefore, implicitly reject the bodily continuity criterion of personal identity. Instead, our intuitions in Phil’s case seem on the whole in line with the teachings of Locke’s memory-centric theory of personal identity. Phil’s Dayn+1 memory of Dayn confirms us in the belief that we have not simply a Phil-look-alike on Dayn+1, but Phil, since Phil has continuity of memory of his own experiences across the Days.

When we turn to Rita, however, things become more complicated. Common sense tells us that Rita is the same person on February 1 and on February 3 – when it comes, at last! Common sense may initially also want to put within that same identity all the Ritas of the many thousands of Days. But here common sense is out of its depth. Compare the Day on which in his TV broadcast Phil calls the groundhog a ‘rat’ and denounces the Punxsutawney officials as ‘damned hypocrites’, with the Day on which he renders his heart warming encomium for the town, its citizens, and its groundhog for the TV segment. On each of these days, up until her first contact with Phil, there is no reason to think that the respective Ritas are anything but identical to Rita of February 1. But post-Phil-contact, very different things start happening to Rita, causing problems for both standard theories of personal identity.

On the memory theory, the post-Phil-contact Ritas of different Days cannot be identical. They have different memories because they have experienced different things. The continuity memory criterion for personal identity might also seem to suggest that they are both identical to February 1 Rita, but that cannot be. If they are generating different memories, they must be non-identical, and so cannot both be identical to the original Rita (If x≠y then not both x=z and y=z). There is no reason to consider any Day special for purposes of memory theory identity, with the possible exception of the last Day. Therefore the Ritas on almost all the Days will be non-identical both to each other and to the Rita of February 1 and February 3. More generally (at least on a natural understanding of the memory theory), no one who falls within Phil’s causal cone on any Day will be identical to herself or himself on any other Day. Those outside Punxsutawney and beyond the reach of Phil’s television broadcast suffer no such identity loss even though they loop as well, since they have identical memories on each Day.

Bodily continuity theories will also declare the Ritas non-identical. Let’s focus on 3pm of each Day. At that time, the Ritas of different Days are in different spatial locations and doing different things, so they cannot be the same person.

If you want all the Ritas to be one and the same person, your best bet is to apply the bodily continuity theory in supertime. It will, however, not be a winning bet. Yes, so far as we know, there is a Rita during every moment of supertime, and at no moment in supertime is she in two different places doing two different things. Still, she suffers a significant daily discontinuity. At the end of each Day save the last, she does a spatial jump, at the very least dematerializing on one side of her hotel bed and rematerializing on the other. Worse, there is a raft of bodily changes, most interestingly ‘erasures’ in the memory sections of her brain, as she returns to the exact physical status of the first moment of the first Day. This is not the kind of physical continuity that the theory requires.

The Larry Theory & Partial Personal Identity

There is a different solution to the question of their personal identity that will seem plausible to all the non-Phil characters, Rita possibly excepted – if Phil comes clean to her. Take cameraman Larry (Chris Elliott) as an example. On a Lockean solution, from Larry’s point of view, Larry of the final Day is identical to Feb 1 Larry and Feb 3 Larry. Feb 3 Larry has a memory only of the last loop of Groundhog Day, and also a memory of Feb 1. Thus the Larry of the last Groundhog Day is in memory continuity with Larry before and after that day, and so these Larrys are memory-theory identical. The Larrys of all the other Days are left out in the cold, identity-wise.

Let’s call this the Larry-theory, and ask whether Phil and Rita should adopt it. The Larry-theory would have the advantage for Phil that he would not need to apologize to Rita on Feb 3 for his attempts to manipulate and seduce her on some of the earlier Days. He should feel guilty towards the Ritas of those days, but they will have mayfly-ed out of existence, and Feb 3 Rita won’t remember them.

Once informed of the whole story, however, Rita would be letting Phil off too easy if she accepted this line. Even if the breakdown of physical and memory continuity makes it difficult to identify all the Ritas of all the Days with the Rita who heads towards a happy ever after with Phil on February 3, that final Rita would, and should, have more than a passing interest in the Ritas of the earlier Days. They bear a close relation to her, even if they are not her. It is crude, but not wrong, to say that they were ‘in large part’ her. If Phil confesses his seduction attempts to Rita, she will feel that a wrong had been done to persons not distinct from her in anything like the usual way.

The movie, then, gives Rita, and us, reasons for adopting a position on personal identity reminiscent of Derek Parfit’s (see for instance, ‘Personal Identity’, The Philosophical Review 80, 1971): there are metaphysical possibilities intermediate between personal identity and personal distinctness. Here, the whole crowd of Ritas have a common physical and memory predecessor: Feb 1 Rita. They also have all but a few hours of their entire remembered history in common. They also share (almost) all their values and projects, and even their inmost secrets and desires. They not only look the same; they are ticklish in exactly the same spots. It is impossible not to conclude that the Larry-theory, which gives continuing identity only to the people of the last Day, leaves out something important about the connection that Rita will, and should, feel to the Ritas of the other loops. Though not the identical person, they are also not different persons.

This all raises the possibility – which I think we should all take seriously – that sameness of person may be a Parfitian gradualism. To apply this idea to real life: you may not be identical to the person you were fifteen years ago, not only in the metaphorical sense of having personality changes, but in a metaphysical respect that should guide your conduct. Rather, you are only partially, or perhaps mostly, the same person. This means that if you are a twenty-something, you may not face death, or you may have only minor equity in the person bearing your name who finally dies. The dark, although somehow not very scary, flip side, is that you will have largely faded out before then. A prudent corollary: make sure the current stage of your life is not merely preparation for later stages, but itself enjoys a great deal of what makes life worth living. If you are a student, you may exempt exam period from this advice.


We have seen Groundhog Day’s plot outline many times before: boy meets girl; boy doesn’t get girl; boy doesn’t get girl again; boy still doesn’t get girl; boy finally gets girl. It is a good thing Groundhog Day is so long on temporal metaphysics. What, otherwise, would have been the point?

© Dr Lawrence Crocker 2020

Lawrence Crocker studied philosophy at Yale and Harvard, and taught at the University of Washington before a career as a lawyer. He latterly taught philosophy at Dartmouth College in New Hampshire where he is now a Visiting Scholar.

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