Wednesday, November 2, 2016

Cessation of existence and theories of persistence

Suppose I could get into a time machine and instantly travel forward by a hundred years. Then over the next hundred (external) years I don’t exist. But this non-existence is not intrinsically a harm to me (it might be accidentally a harm if over these ten years I miss out on things). So a temporary cessation of existence is not an intrinsic harm to me. On the other hand, a permanent cessation of existence surely is an intrinsic harm to me.

These observations have interesting connections with theories of persistence and time. First, observe that whether a cessation of existence is bad for me depends on whether I will come back into existence. This fits neatly with four-dimensionalism and less neatly with three-dimensionalism. If I am a four-dimensional entity, it makes perfect sense that as such I would have an overall well-being, and that this overall well-being should depend on the overall shape and size of my four-dimensional life, including my future life. Hence it makes sense that whether I undergo a permanent or impermanent cessation of existence makes a serious difference to me.

But suppose I am three-dimensional and consider these two scenarios:

  1. In 2017 I will permanently cease to exist.

  2. In 2017 I will temporarily cease to exist and come back into existence in 2117.

I am surely worse off in (1). But if I am three-dimensional, then to be worse off, I need to be worse off as a three-dimensional being, at some time or other. Prior to 2117, I’m on par as a three-dimensional being in the two scenarios. So if there is to be a difference in well-being, it must have something to do with my state after 2117.

But it seems false that, say, in 2118, I am worse off in (1) than in (2). For how can I be better or worse off when I don’t exist?

The three-dimensionalist’s best move, I think, is to say that I am actually worse off prior to 2017 in scenario (1) than in scenario (2). For, prior to 2017, it is true in scenario (1) that I will permanently cease to exist while in (2) it is false that I will do so.

It can indeed happen that one is worse off at time t1 in virtue of how things will be at a later time t2. Perhaps the athlete who attains a world-record that won’t be beaten for ten years is worse off at the time of the record than the athlete who attains a world-record that won’t be beaten for a hundred years. Perhaps I am worse off when publishing a book that will be ignored than when publishing a book that will be taken seriously. But these are differences in external well-being, like the kind of well-being we have in virtue of our friends doing badly or well. And it is counterintuitive that permanent cessation of existence is only a harm to one’s external well-being. (The same problem afflicts Thomas Nagel’s theory that the badness of death has to do with unfinished projects.)

The problem is worst on open future views. For on open future views, prior to the cessation of existence there may be no fact of the matter of whether I will come back into existence, and hence no difference in well-being.

The problem is also particularly pressing on exdurantist views on which I am a three-dimensional stage, and future stages are numerically different from me. For then the difference, prior to 2017, between the two scenarios is a difference about what will happen to something numerically different from me.

The problem is also particularly pressing on presentist and growing block views, for it is odd to say that I am better or worse off in virtue of non-existent future events.

Of the three-dimensionalists, probably the best off is the eternalist endurantist. But even there the assimilation of the difference between (1) and (2) to external well-being is problematic.


Michael Gonzalez said...

Doesn't the three-dimensionalist open-futurist necessarily believe that time travel is impossible? There is no future time to travel into. This scenario would go somewhere in the absurdly large pile of absurdities that are entailed by four-dimensionalism.

Really, even if the 3D/OP-ist got knocked in the head hard enough to think that time travel to the future is possible, but you just cease existing until that later moment finally comes along, they would be faced with a situation that is 100% identical any other sort of cessation and return to existence (e.g. questions about the resurrection of the dead). It is actually meaningless to call that "time travel", since all it is is going out of being and then coming into being.

Michael Gonzalez said...

Even the differences in "external well-being" are meaningless to a 3D/OP-ist, since there is no fact at all about whether your book will be read or the athlete will be surpassed.

It seems that these puzzles for the 3D/OP-ist are constructed in 4D-ist terms.

Heath White said...

Aristotle says you can only really tell if someone was happy once they are dead. That would seem to be an extrinsic kind of well-being, so there is at least precedent.

Michael Gonzalez said...

I'm not even sure what that statement means, so I don't see how it's a precedent. Even if it were a true rule... to the best of my ability to understand it, it would just forbid us from calling a person happy until after they are dead. That doesn't mean that their happiness at any give moment, or even overall, was predicated on some later moment. It just means we should withhold judgment until their death.

Alexander R Pruss said...


Actually, all A-theorists think futureward time travel is possible, at 1 second per second. :-) The question is whether instant time travel is possible.

If not, the argument just needs an extra pair of steps:

1. If per impossibile time travel were possible, there would be no harm in futureward time travel.
2. If there would be no harm in futureward time travel, there would be no harm in a temporary cessation of existence.

Good catch that the external stuff is problematic for 3D+OF. That's another problem for 3D+OF.

Michael Gonzalez said...

I would argue that 3D-OF-ists do not think "time travel" is a meaningful phrase; even if at one second per second. What is happening is not travel; it is a dynamic morphing of reality.

If you add that pair of steps, it just further reinforces why future time travel is absurd on the 3D+OF view. We already have lots of reasons to think that; this would just be one more.

The "external stuff" isn't necessarily a problem for 3D+OF, since we find such statements prima facie meaningless. What does it mean to say that, at this moment, I am worse off publishing my book because it "will be" ignored? And what if it is ignored... for 1,000 years, but is then discovered by scholars and revealed to be the greatest literary gem of our time... and then is forgotten again a million years after that because humanity is post-literate.... I mean, the vicissitudes of the possible futures really don't have any bearing on the value of my book at this moment, do they?

Alexander R Pruss said...

In any case, it's clear that temporary cessation is much less bad than permanent cessation. And that's enough to generate the problem in the post.

If you're kidnapped by a mad metaphysician who tells you that he's got a machine that will make you cease to exist for a minute, you won't worry much about the minute-long cessation of existence. You'll worry whether it'll hurt, whether you'll come back into existence, etc.

Michael Gonzalez said...

I agree completely. But, is temporary cessation even possible? Even on a 4D view, wouldn't that mean that there are two separate 4D objects with a gap between them?