Philosophy, et cetera

Suppose that our conscious experiences have a certain minimum duration, say 100 ms.  Take a subject experiencing a second of pleasure, and let 't1' denote the first 50 ms time period, 't2' the next 50 ms, and so on through to 't20'.  So the subject experiences pleasure from t1 - t20.  Do they experience pleasure at t1 (and accrue a proportionate momentary welfare boost at this time)?

I'm inclined to answer 'yes'.  But this may seem to entail that both whether you're experiencing pleasure at a time and whether you accrue positive momentary welfare can be extrinsic, not fixed by the intrinsic properties of the moment.  After all, if the agent had been knocked unconscious after t1, then they would not have experienced any pleasure during this period due to the associated neural activity lasting for less than the minimum experiential duration.  Their neural activity at t1 will only get to (partly) constitute a pleasant experience if it continues on for at least another 50 ms.  This gets especially puzzling if one posits an open future.  It might then be indeterminate at t1 whether the agent is currently experiencing pleasure -- the facts about the agent's t1-experiences would not be settled until a later time (perhaps at t3 they get retroactively 'fixed').  That seems weird.

Inspired by Princeton's recent (and very interesting) "Workshop on Well-being", I've been thinking about the debate between Bradley and Dorsey over the question: Where in time should Desire Theorists "locate" the benefit of a satisfied future-directed desire? At the time (t1) of the person's having the desire, or the later time (t2) where the object of the desire, i.e. the desired "good", is located?

I'm not sold on the idea that harms and benefits must be temporally located at all.  But supposing we do want to locate the benefit here, the former option -- locating it at the time of the state of desire -- seems to me to make most sense.  This may be illuminated by translating welfare talk into 'for the sake of' talk.

M. Oreste Fiocco has a curious paper, 'Consequentialism and the World in Time', forthcoming in Ratio.  It contains a number of arguments that strike me as very confused.

One central argument may be characterized as follows:
(1) Consequentialism is committed to "temporal homogeneity" (i.e. Eternalism)
(2) The truth or falsity of consequentialism is non-contingent
(3) Temporal homogeneity is contingent
So, Consequentialism is false.

Towards the end of his (1983) 'Value and Population Size', Thomas Hurka considers the objection that value holism might sometimes mandate killing those of (positive but) below average welfare, so as to raise the average. He responds:

It is foolish to think that the consequentialist principles we use to assess the values of different populations could ever be the only principles in an acceptable moral theory. They have to be accompanied by supplementary principles setting constraints which we must not violate while pursuing our population goals and which we must not violate in particular by taking the lives of existing people. If we are to assess population principles as population principles, then we must assess them in circumstances where these constraints do not apply, that is, in circumstances where only increases and not decreases in the human population are in question.

This looks like the kind of mistake I had in mind when I wrote 'Anti-Consequentialism and Axiological Refinements': what Hurka interprets as a need to go beyond consequentialism, I see as a need to refine our axiology. If Hurka's right, then we should think something like the following: "Though it'd violate the moral rules to help bring about this outcome in any way, I must say it'd be really grand if all those happy folks of below average welfare would just drop dead. Here's hoping for some well-placed lightning strikes!"

The best rules (or dispositions) and the best actions may come apart in theory. Fortunately, a reflective agent may be able to limit the damage by means of what Ainslie (1975) calls "private side bets".

Consider Kavka's toxin puzzle. Many philosophers think that a rational person couldn't win the prize, because by the next day they would no longer have any reason to drink the toxin -- and, recognizing this, they will be presently unable to intend to so act. To be successful in situations like this, agents require the internal power to 'bootstrap' additional reasons into existence. (Note that the terms of the game specify that you're not allowed to employ external incentives to win the prize. So you can't make a bet with anyone else that would give you additional reason to follow through and drink the toxin.) Intuitively, the solution seems to be that you should just make a resolute commitment - a promise to yourself - to drink the toxin. The hope is that this internal act of self-promising will provide you with a new reason - an internal incentive - to go ahead and drink the toxin, thus allowing you to intend this action and to reap the rewards.

Jeremy is unsure what to make of the idea of 'timeless' facts, if this is not just to say that they are true at all times. One way to grasp the distinction is to start with a temporary object, like a speck of dust, and then imagine that it just happened to exist at all times. Then 'the speck exists (now)' is true at all times, but in a very different way from how 'the speck exists at t1' is true at all times. Only the latter fact is timeless.

This difference may also be revealed in the modal properties. A timeless proposition will typically still be true even if you added extra times. (An exception: call the final moment of the universe tN. It's a timeless fact that tN is the final moment. But if we added an additional moment, tN+1, then this would no longer be true at all.) On the other hand, something merely contingently 'true at all times' might not remain true if we added an additional time, say a moment that no longer contains any specks of dust. [Are there exceptions in this direction too? Try to think of a temporally immanent fact that is nonetheless necessary, so that it would also be true in any additional times that might be added. Perhaps "that there is space (now)"?]

I guess the principled way to state the distinction is to say that some things are true at all times because of what's immanent, present, or 'going on' at each time; whereas other (timeless) propositions are true at all times for a "cheaper" reason. A timeless truth doesn't need truthmakers at each time; it just has a single truthmaker (say, the speck's existing at time t1) which suffices for it to be true at all times, whatever else may be going on at them. Though technically true at all times, it isn't really about all times in any deep sense.

Anyone got a neater way to word all this?

Ben Bradley's main argument for hedonism (in his recent diavlog with Roy Sorensen) seemed to be that other theories run into "difficulties" when it comes to specifying when certain alleged harms occurred. For example, most non-hedonists think that achieving your goals makes your life better. But suppose that you work hard to preserve a great work of art, only to have some vandal come along and destroy it after you die -- making it so that all your hard work was in vain. I think it's clear that this is bad for you, but Bradley asks, when is it bad for you? Roughly: "It can't be bad for you when you're alive, since your desire isn't thwarted yet, but nor can it be bad for you once you're dead, since you no longer exist to suffer harms. So it can't be bad for you at all."

I find pretty much every step of that argument dubious. Note that the first premise is technically false. Time-indexed propositions (e.g. "that the artwork survives beyond time t1") have their truth-values timelessly, so if you currently desire that the artwork survive beyond future time t1, and it doesn't so survive, then technically the desire is ("already") thwarted, in virtue of this future state of affairs.

The second premise is also dubious in light of 4-dimensionalism, as Bradley himself acknowledges and relies upon in explaining why death itself is bad for you. (Even after you die, you nonetheless exist in the past, and so the fact that your life wasn't longer can be bad for that past entity. And I doubt much really hangs on the metaphysics; presumably even presentists would want some way of saying things like this.)

Most importantly, it isn't at all clear why we should think that harms must have a temporal location at all. A harm is just whatever makes your life worse (less desirable). There doesn't have to be a particular time at which it is worse. Bradley's conclusion would only follow given the additional assumption of welfare atomism, i.e. the view that the welfare value of a life is simply the sum of the values of each individual moment. But there's no good reason to grant this assumption (especially for non-hedonists). We should instead be value holists, as I argue here. (See also Parfit on Global Preferences.)

(It's odd; in the discussion of the "James Dean paradox", Bradley effectively notes that the vast majority of people are in fact implicitly committed to value holism. We think that the overall 'shape' of the life matters, rather than only caring about the sum total of happiness contained therein. Bradley just dismisses this as "irrational", without argument.)

Indeed, even if we're hedonists, it seems that negative facts -- like the fact that you didn't get to live longer or experience more in the time that you had -- can be undesirable for your sake, and hence qualify as 'harms' in the broad sense of the term, even though these are 'global', atemporal features of your life. And on every plausible view, we can be harmed by events that take place before we're born. It doesn't seem that much of a stretch to acknowledge a similar phenomenon in the opposite direction.

The Ethical Werewolf asks:

What modality applies to the impossibility of changing the past? Is changing the past logically impossible, metaphysically impossible, or physically impossible?

There are many possible questions here. On one popular reading, to "change" the past (or the future, for that matter) is logically impossible: given that Bob was shot at time t, it is not logically compatible with this to make the world such that Bob was not shot at time t. So we cannot "change" the past in the sense that "first" time t is one way, and "later"(?) that very same moment somehow differs. Change is when one moment differs from another; a moment cannot differ from itself. But this is a trivial kind of 'impossibility'.

At the other extreme, we may refrain from taking any merely contingent facts as 'given', and ask abstractly: is it possible that I perform some action φ, such that Bob isn't (and never was) shot at time t? And that seems possible in almost every sense: there's a physically possible world where I φ and Bob isn't shot. It just isn't this one. (And, more importantly, neither is it accessible in any important sense.)

So the real question must lie somewhere in between. Most plausibly, it depends on some notion of "dynamic" or time-relative physical (causal) possibility. That is, we take the present moment as given, and ask whether we have (sufficient) causal influence over what happens at time t. So the modality of my inability to (now) influence the past is simply a time-relative version of the modality barring me from time travel. 'Physical impossibility given my current circumstances', perhaps?

People often confuse temporality and modality -- thinking that what 'will' be, 'must' be. This is simply a mistake. To illustrate, let Q be the proposition that tomorrow I φ. Distinguish:

(i) The actual truth of Q.

This is just to say that I will happen to φ.

(ii) Determinism about Q

This adds the claim that the conjunction of some past state P0 and the laws of nature L together entail that I will φ. Not only is Q actually true, but its negation is inconsistent with P0 & L. So in this sense I must φ. But I may retain some causal responsibility, in the sense that if I had been different, so would have been the outcome. It's merely the case that (given P0 and L) I could not have been different in the first place.

(iii) Fatalism about Q

This adds the yet further claim that Q is robustly overdetermined, such that I still would have ended up φ-ing even if my thoughts, desires, and intentions had somehow been different. So even various alternative past states P1, or P2, etc., when conjoined with L, entail Q. If it hadn't happened the one way, it would have happened some other way. This yields a much stronger sense in which I 'must' φ: even had things been different, my φ-ing could not have been avoided.

These various modalities are often confused. So it is important to be clear that just because something will occur, does not mean that there is any stronger sense in which it 'must' or is 'guaranteed' to occur. If you know beforehand, it may be 'certain' in an epistemic sense. But that is of no interest here; what matters is the metaphysical question of how things are in themselves. Compare the past: we may have certain knowledge that some past event E occurred, but that alone does not mean that E itself was in any way guaranteed or 'fated' to occur. As things turned out, E did occur, but that fact is obviously compatible with the claim that things could have turned out differently. And exactly the same is true of future events, such as my φ-ing. Actuality does not imply necessity; 'is' (or 'will') does not imply 'must'.

(In practice, others will rarely be in a position to safely assert 'Richard will φ' in advance unless I am unable to do otherwise. After all, how else can they be so sure? I might change my mind -- especially if I overhear them, I might change my mind simply to prove them wrong! So, in practice we are used to 'will' assertions being correlated with 'must' facts. This practical correlation might help explain why we are so easily tempted to conflate the two ideas, but clear thinking requires us to disentangle such associations.)

One may object (as did my confused past self, circa 2004): "If Q is true, then I cannot actually fail to φ, for that would render Q false, contrary to the assumption." But this is deceptive rhetoric. It is true, but utterly trivial, that one cannot hold the truth of Q fixed and at the same time make it false. But there is no substantive necessity here. For all that's been said, it might be entirely within my power whether I φ, and hence whether Q is actually true or false. If Q is actually true, then that's just to say that I won't actually fail to φ, but it says nothing about what I could have done. Don't let the order of words on the screen fool you: the direction of explanation flows from my contingent action to the truth of the proposition. (Q is true because I φ. It would get things backwards to think that I φ because Q is somehow antecedently true.)

A related caution: it may be true (now) that tomorrow I φ. But that makes it sound like the truth exists prior to the event. This is, again, a mere quirk of language. To say it's true that tomorrow I φ is simply to say that tomorrow I φ. It's a claim about tomorrow's events, and whether it's true or not depends entirely on those events. If it turns out that I φ, then we can say it was "true" all along. But you shouldn't be tempted to read anything deeper into such claims. (In particular, it's not to say the future truth is somehow 'contained within' or derivable from the present state of affairs -- determinism is a further claim!)

A final source of confusion stems from conflating descriptive and rigidly designating interpretations of 'the actual world'. Let '@' rigidly designate what philosophers call "the actual world" (and what really means the actual world-description, or a complete list of all the propositions that happen to be actually true). Now one might worry that it's a necessary truth that Q is true in @ -- or that 'actually Q' expresses a necessary truth. So we lack the power to change what's true in the actual world (@); but the actual world is the world we care about, so (the argument goes) we lack the only power we ever cared to have.

Can you spot the fallacy? We are not essentially concerned with @ -- in itself, @ is a mere world-description, a way the concrete universe could be. What we care about is the concrete universe, and how it turns out. In particular, if the universe turns out as @ describes (so that @ is the "actual world[-description]") then we care about that, for the universe's sake. Note that the power we're really concerned with is the power to change the universe, not some particular description thereof. In short: we can't change the description (de re) of the universe, but we can change the universe itself so that it meets a different description. And of course it's the latter power that we really cared about all along.

This is interesting:

If the brain sped up when in danger, the researchers theorized, numbers on the perceptual chronometers would appear slow enough to read while volunteers fell. Instead, the scientists found that volunteers could not read the numbers at faster-than-normal speeds.

"We discovered that people are not like Neo in The Matrix, dodging bullets in slow-mo," Eagleman said.

Instead, such time warping seems to be a trick played by one's memory. When a person is scared, a brain area called the amygdala becomes more active, laying down an extra set of memories that go along with those normally taken care of by other parts of the brain. "In this way, frightening events are associated with richer and denser memories," Eagleman explained. "And the more memory you have of an event, the longer you believe it took."

Eagleman added this illusion "is related to the phenomenon that time seems to speed up as you grow older. When you're a child, you lay down rich memories for all your experiences; when you're older, you've seen it all before and lay down fewer memories. Therefore, when a child looks back at the end of a summer, it seems to have lasted forever; adults think it zoomed by."

Never mind physical (un)responsiveness; does your experience last longer when scared? Do you obtain more pleasure and pain by time seeming to you to pass slower? Does this give us additional reason to bring joy to children (and give less priority to aiding the elderly)?

I'm beginning to think that the way to count or measure an experience is not through its objective duration at all, but simply its richness of representational content (which may better reflect felt duration in any case). This may support my claim that multiple experiences matter less the less qualitatively different they are. Merely repeating the same old information over and over again does nothing to enrich the representation, after all.

Thoughts?

Inspired by the discussion at Pea Soup, let's distinguish:

(1) the external, physical duration of a phenomenal experience,
(2) the internal, felt duration of the experience, and
(3) the believed duration of the experience.

To illustrate the differences: Experience machine A gives you pleasant experiences for 100 years. Machine B (allegedly) gives you all the same experiences, feeling exactly the same from the inside, but packed into just a single real-time day. Machine C gives you one day of pleasure, and then simply implants in you the false belief that it felt like it lasted for 100 years.

A key question is whether dimension (2) is stable and independent of the others, i.e. whether Machines B and C are really distinct. But first, we must consider whether qualia (conscious experiences) are to be identified with brain states or their contents:

Our talk of conscious experience risks conflating two distinct objects: the qualities (properties) of the vehicular experience or representation itself, versus the qualities represented in the experience. It's plausible to think that we can access only the latter. For information to be available to us, it must be represented in our minds...

This includes experience itself: there may be facts about it of which we remain unaware. This is plausibly true of the temporal properties of our experiences, for instance. It seems to me that I experience A before experiencing B, but in actual fact all I have access to is my mental representation as of "A followed by B"... I don't really have a "mental eye" in my head to tell me what's going on in there, independently of what eventually enters into a conscious representation. Our introspective capabilities are hence severely limited.

Clearly, the brain states themselves last only a day in Machine B's case. But they represent 100 years' worth of happenings. How are we to describe this? Here are two options:

(i) What you experience is the brain state itself, and hence lasts for only a day; it's just that you're left with the false impression that it lasted longer than that. Machine B was misdescribed: in fact it is no different from C.

(ii) What you experience is the content as represented by the brain state, viz. 100 years. It is truly the same content/experience as given by Machine A; it's merely the physical bases of the experiences which differ, and that's nothing to care about.

I'm inclined towards (ii). But if experiences can so radically come apart from their underlying brain states, we may question whether Machine C is actually as deceptive as we'd assumed. If the implanted belief changes the contents represented in our phenomenal states, perhaps this actually gives us 100 years of experiences?

One reason for doubting this is reflection on the paucity of the representation. It's one thing to write a story which says "100 years passed", and quite another to fill out the details for 100 years' worth of fictional events. So, if we think of Machine A as taking a long time to impart rich informational content (lots of pleasure), and Machine C as taking a very short time to impart a very thin representation (very little pleasure), the question whether Machine B imparts a lot or only a little pleasure comes down to the richness of the representations it implants. Sound right?

If one asks whether A and B (objects existing at two different times, or possible worlds, say) are really one and the same object, is this a substantive metaphysical question? I think it is not. Consider the following illustration:

This is how an armless person persists through time. S1 is the momentary stage that exists at t1, and S2 likewise at t2. C is the complete aggregate of all the momentary person-stages from t1 to t2. Now, one might apply the name 'A' at t1, and 'B' at t2, and ask whether A is B. But there are no interesting questions to ask here. It's trivial that S1 is not S2, if that's what we mean. Or, if we instead mean to refer to the temporally extended object C both times, it is similarly trivial that C is identical to itself.

Note that we may similarly construct gerrymandered objects out of completely unrelated temporal parts. For any two distinct stages whatsoever, it is trivial that (1) they are not themselves numerically identical; and (2) we may call them both temporal parts of some larger aggregate. (If you don't like talk of aggregations, we can restate the point in terms of temporal counterparts. Any two stages are counterpart-related by some criterion or other, and our choice of criterion is metaphysically arbitrary.) We merely have practical reasons for carving the world up in some ways rather than others. Gerrymandered objects may be less useful to talk about, but that's not to impugn their ontological status.

Maybe you don't like any kind of 4-dimensionalism or "temporal parts" talk. That's okay, we can restate the point in the language of enduring 3-d objects. We simply need to say that there are arbitrarily many objects coinciding in any given region of space, for all the various possible "persistence criteria" we might want to apply across times. Consider the famous example of a clay statue. Can it survive being turned to gold by Midas' touch? Well, the statue can, but the clay can't. Conversely, the lump of clay can survive being squished into a nondescript blob, but the statue cannot. And we might just as well choose to say there is an object there that "endures" just in case it turns into a bird and flies away. Why not? It's not as though all this persistence talk is reflecting anything deep about the world. We could apply any criteria we want; it's all mere convention.

The alternative view is what Ted Sider (in his (2001) 'Criteria of Personal Identity', p.194) calls "chaste endurantism", i.e. the conjunction of claims (1) objects - no mere temporal parts - are wholly present at multiple moments, and (2) "distinct entities never coincide". But the case of the statue and the clay suggests that this position is a non-starter. There are various criteria we might use to determine whether an object counts as persisting into the future under any given scenario, and no reason to think that any one of these is the only legitimate or "true" criterion.

So I tend to think that the identity facts, such as they are, do not much matter. Indeed, we may completely describe a scenario without talking about the identities of the things in it at all. We would then know all there is to know about how the world (scenario) is; the remaining question is merely how to describe it -- which persistence conditions to apply, or which temporal aggregates to talk about.

"The experience of being dead should never be expected to any degree at all, because there is no such experience." So writes David Lewis in 'How Many Lives Has Schrodinger's Cat?' (p.17) But perhaps we can have negative expectations, in the sense of not positively expecting any further experiences.

What if I split, amoeba-style, into two future persons, one of whom is promptly shot? In general, I should split my expectations evenly between my future branches. Perhaps I should anticipate the experiences of each branch, separately. (I do not, of course, experience both lives together, in any mutually-accessible kind of way.) If one branch has no experiences at all - being killed before ever awakening, say - then all there is to anticipate is the other, surviving branch. But if it gets to experience a little before dying, then it would seem one allotment of my expectations should capture precisely this: to experience seeing the bullet approaching (or whatever), and then no more.

This is important because if the "no collapse" (or many-worlds) interpretation of Quantum Mechanics is correct, then we are actually splitting all the time. If you shoot me, there exists some (extremely low intensity) state in the superposition in which the bullet passes right through me. However often I die, there is always some version of me that survives. Should I expect, then, to be immortal? Lewis thinks so (p.19):

Suppose you're fairly sure that there are no collapses, and you're willing to run a risk in the service of truth. Go and wander about on a busy road, preferably a few minutes after closing time. When and if you find yourself still alive, you will have excellent evidence [for the no-collapse view]. If that's not yet enough to convince you, try the experiment a few more times.

What should you expect to happen?
(1) You miraculously emerge unscathed (perhaps the cars pass right through you by some quantum fluke).
(2) You get hit by a car, and then have no further experiences (due to being dead).
(3) You get hit by a car, but then miraculously survive (perhaps your crushed body reassembles itself by some quantum fluke).

On the no collapse view, all these outcomes occur, but (presumably) the second does so with much higher frequency or "intensity". Still, even if the overwhelmingly majority of superimposed states involve your getting hit by a car, you will always have some branch that survives this. So there are always further experiences to anticipate. Does this mean we should never anticipate ending up on a dead branch, i.e. one that has no further experiences?

It's not quite enough to ask whether we should expect to be immortal. On the no-collapse view, we are undoubtedly immortal, in the sense that we will always have some surviving branch. But we also die a lot, in that we have a great many terminating branches! So the real question is whether we should ever expect to die. Can our expectations be distributed over branches that contain no further experiences? Or are they restricted to the survivors only?

Do debates in the metaphysics of time affect what we should care about? If eternalism is true, for example, should we be more or less obsessed with non-present events? If presentism is true, can that justify temporal bias (in favour of the near future, say)?

David Velleman ('So it goes', p.20) writes:

We can't stop the self from seeming to endure, or stop time from seeming to pass, but we can cope with these phenomena better, given the knowledge that they are merely phenomenal...

I have a disconcerting tendency to live different parts of my life all at once -- to relive the past and pre-live the future even while I'm trying to live in the present. And even as I relive my past in a memory, it is at the same time speeding away from me, as there comes bearing down on me a future that I am pre-living in anticipation. It's as if too many parts of my life are on the table at once, and yet somehow they are continually being served up and snatched away like dishes in a restaurant whose wait-staff is too impatient to let me eat...

The realization that I am of the moment -- that is, a momentary part of a temporally extended self -- can remind me to be in the moment.

But why is this? I guess the thought is that if the past no longer exists, our emotional attachment to it may tempt us to imaginatively "bring" it into the present. Eternalism reassures us that the past is safe and sound right where it is, so we need not be so clingy. On the other hand, as a classmate pointed out to me, we may think that the eternal reality of a past event is all the more reason to dwell on it. (I'm more inclined to the view that the metaphysics makes no difference either way. But that may just be because I can't really see what the dispute amounts to -- presentism seems inconceivable to me.)

What of temporal bias? Could "the moving now" better justify the relief we feel when bad events are past? Parfit (R&P, p.180) suggests an argument:

Suppose we allow the metaphor that the scope of 'now' moves into the future. This explains why, of the three attitudes to time, one [the bias towards the near] is irrational, and the other two [biases towards the future, and the present] are rationally required. Pains matter only because of what they are like when they are in the present, or under the scope of 'now'. This is why we must care more about our pains when we are now in pain. 'Now' moves into the future. This is why past pains do not matter. Once pains are past, they will only move away from the scope of 'now'. Things are different with nearness in the future. Time's passage does not justify caring more about the near future since, however distant future pains are, they will come within the scope of 'now'.

But, likewise, however distant past pains are, they have been within the scope of 'now'. Why isn't that enough to make them matter? (After all, concern for the future precludes one from claiming that pains matter only while they are present.) So the mere fact (if it is one) that 'now' moves into the future doesn't explain why past pains do not matter.

One might introduce a "growing block" theory to introduce the needed asymmetry between past and future. On that view, the past exists, whereas the future is still open. But this seems to give precisely the wrong result. Assuming we should care more about existing pains than non-existent ones, the growing-block theorist is committed to favouring the past over the future!

Another challenge for temporal neutrality may be posed by those who deny the commonsense view there is an enduring self or ego that persists through time while being wholly present at each moment. For the alternative is to see personal identity as a mere construction of sorts, perhaps consisting in nothing more than the right sorts of physical and psychological connections between various temporal parts, or momentary time-slices of a person. In that case, it may seem that what I am, at the most fundamental level, is not a whole temporally-extended person at all, but just a momentary time-slice. The relation my momentary self bears to my future selves then rather resembles the relation my person bears to other - more or less similar - persons. However, most of us think that it may be quite rational to be personally biased, in the sense of favouring some persons (e.g. ourselves and those close to us) over others. So why is it not likewise rationally permissible to favour some momentary time-slices (e.g. our present moment, and those close to us-now) over others?

I grant the underlying metaphysical picture, and will remain neutral on whether full-blown personal neutrality is rationally required. So I agree that if one were to psychologically self-identify with one’s momentary time-slice only, then bias against later time-slices could reasonably follow. For in such a case, one would arguably no longer be a person with a future at all. This is implied by the following endorsement condition (EC) on the construction of personal identity:

(EC) Any temporal proper part of a person must (at least implicitly) endorse its incorporation into the temporally-extended whole.

The sort of implicit endorsement I have in mind is satisfied by conceiving of oneself as a temporally-extended person, for example identifying with the subject of one’s memories, anticipating future experiences, etc. We may imagine someone - call her Mini - who, upon rejecting endurantism about the self, goes on to purge herself of all such thoughts. By failing to imaginatively project herself beyond the confines of her present moment or otherwise consent to incorporation into a temporally extended whole, Mini’s person would extend no further than the time-slice. The subsequent time-slices will of course bear various relations to her, being continuous in many notable respects, but they no more comprise a unified person than do people with similar interests automatically comprise a club. Persons, on this view, are voluntary associations.

Mini is not biased against her future, then, because she has no future. We do better to describe the situation as one in which she is biased against the people who later inhabit her body. If we reject the strict requirements of personal neutrality, then we may consider Mini to be reasonable in her bias. But it is not fundamentally temporal bias. It is just an unusual case of personal bias.

I previously argued that Parfit's affect-based objections to temporal neutrality fail. As Alex pointed out, though, Parfit also offers a more direct objection. As part of the 'bias towards the future', he thinks that we might really prefer to suffer a greater pain in the past rather than a lesser pain in the future. Now, assuming that we cannot affect the past, it is difficult to see what this preference amounts to, at least if it is meant to be distinct from mere affect, e.g. relief upon learning that a painful operation is now past. There is no genuinely possible choice in which the preference could be revealed. But perhaps we can imagine an impossible choice, involving time travel or divine intervention in foreknowledge of one’s backward-looking prayer. Can we then imagine, in this impossible scenario, reasonably choosing to have one’s pains amplified and shifted into the past?

There are two bad reasons why we may be tempted to affirm this. First, we are used to the equivalence between being over and ceasing to extend in time. So a typical preference for a pain’s being over is inseparable from the preference that it become no longer - a preference that the temporal neutralist can clearly endorse. Second, even if we appreciate that in this special case the past pain is no shorter, we may fail to fully appreciate that it is really experienced at all. By the time we are in the present, our past experiences have already been and gone. We did not experience them the first time through, so it may seem that shifting pains into the past is simply a way to make them disappear altogether! Of course, this intuition illicitly reflects our assumption that we cannot really change the past - an assumption that must be rejected in the scenario under consideration (since we are supposed to be introducing pains into the past that would not be there otherwise).

When we take care to avoid these two mistakes, and instead really vividly appreciate the greater pain that our past self really would suffer if we made the relevant choice, does it still seem so obviously preferable?

[By Jack]

What is the relationship between the series of truths in the world and the times in that world? That is, imagine that: !, @, #, $, % are maximally complete sets of truths (like an ersatz possible world for a world that lasts only an instant) and that time is discrete. How many different possible worlds can there be with this series of truths?:

!, @, #, $, %?

I think the most intuitive answer is one. Here is what makes that answer problematic. There can be two distinct times even though all and only the same things are true at those times. To see this, consider the following series of truths:

!, @, #, $, %, $, #, @, !

Then ask, how many instants are there in this world? I find it exceedingly implausible to say that there are only 5 instants of time in this world, one corresponding to each of the different maximally complete sets of truths. For then, which came first, the time that is corresponds to $ or the time that corresponds to %? This suggests that two non-identical times can realize a maximally complete set of truths.

But now the slippery slope kicks in. Why just two? What about this series of truths?:

!, @, #, @, !, #, !,

This suggests that any number of non-identical times could realize a maximally complete set of truths. But this is unattractive as well. It doesn't seem that we should have possible worlds that differ merely in the identities of the times in their world. [Suppose that t1 can realize # and t2 can realize #, but that t1 is distinct from t2. Now, there might be two different worlds that correspond to the following series of truths: #. One world is simply t1 and the other is simply t2. But that is weird.]

Suppose you will soon be subject to torture and degradation, such that you would prefer to die beforehand. Suicide is not allowed, but you are offered the opportunity to have all traces of your psychological self purged from your brain -- memories, character, talents, etc. Would that help? Would you fear the upcoming torture any less, perhaps believing that it would now be someone else rather than you who endures it?

How about if your psychological traces are completely transferred into the brain of another person, who goes on to live a happy, torture-free life?

Suppose now that the psychological transfer is compulsory, but beforehand you get to choose which body will be subsequently tortured. What would you choose?

(Cases from Bernard Williams, 'The Self and the Future'.)

Is time immanent in the world - reducible, perhaps, to the ticking of an atomic clock - or transcendent, somehow beyond the physical universe? (One of my old Canterbury lecturers gave a great talk on this a couple of years back.) We seem pressed towards a kind of middle ground. No mere clock can be the ultimate standard of time, for a clock may slow down, and that does not mean that the rest of the universe has speed up! No, we take them to be measuring something beyond themselves. The same will be true of any local standard (e.g. the movement of the sun).

Markosian (1993) suggests:

[The change in the sun's position] is also meant to be a stand-in for a more important change, namely, the pure passage of time. Indeed, it seems that our assumption that the sun's position changes at a constant rate amounts to the assumption that the sun's position changes at the rate of fifteen degrees per hour, i.e., that every time the sun moves fifteen degrees across the sky, one hour of pure time passes. So it at least appears that what we are after in trying to determine the rates of various physical processes, such as Bikila's running of the marathon, are the rates at which those processes occur in comparison to the rate of the pure passage of time. (pp.840-1)

I hope we can come up with a better account of this appearance, since "the rate of the pure passage of time" is gibberish. But why should we interpret "fifteen degrees per hour" as relating two changes (the sun through space vs. the present through time)? It seems on the face of it to just be reporting a single change, i.e., that the sun moves fifteen degrees across the sky in the space of one hour. The hour doesn't have to move. Just the sun.

Perhaps the worry is that if time doesn't pass, then the standard of an 'hour' must be defined in terms of immanent physical changes (like the sun's movement, or a clock's ticking). But all measurement is like this. A clock is to time as a ruler is to space. Nobody takes this to mean that we need an objective 'here', extending over space at a rate of one meter per meter, to tell us how long a meter really is in case all our rulers suddenly shrink. Yet Markosian writes (p.841):

suppose that the pure passage of time thesis is false... if it should turn out one day that the motion of the sun in the sky appears to speed up drastically relative to other changes, then we should say, not that the motion of the sun has sped up drastically relative to the pure passage of time, while every other change has maintained its rate, but, rather, simply that the sun's motion has sped up relative to the other normal change.

Why can't we say that the sun has sped up drastically, not relative to any other rate, but just simpliciter? It is moving a greater distance in space for the same interval of time. Simple.

It seems like the real issue here is substantival vs. relational conceptions of space-time. If space-time is like a container, an objective thing in its own right, then universal shrinkage - or slowing - of its contents might be a coherent possibility (even if we couldn't recognize such an event from the inside). If they're merely relational, on the other hand, and so fundamentally about relative proportions, then the idea of all distances or durations universally increasing may make no sense, since to double each component is to leave the ratio the same. (Note that while this is a curious issue in its own right, it's nothing to do with the passage of time.)

In any case, if immanent relations are all that we have access to, we may wonder whether substantive, transcendent space-time could really matter. So it is worth seeking a plausible immanentist theory. We noted at the start that no local standard would do. But perhaps a global generalization would serve better. Plausibly, we seek a frame of reference that yields the greatest amount of stability in our general region. Relative to my heartbeat, the world is in a crazy flux. But my clock, and the sun's movement, and a whole cluster of other natural processes, can be interpreted as each holding a constant rate relative to each other. So we take this general cluster as our standard of time. Any one component may become out of sync with the rest, in which case we will judge it to have changed its pace. The stability of the cluster thus transcends each of its parts (considered individually), whilst remaining wholly immanent. That strikes me as providing as good a basis for measurement as one could hope for.

Markosian (1993) defends the suspicious move from tensed language to tensed reality, by claiming that if we cannot paraphrase away talk of 'presentness' into B-theoretic language (e.g. 'being contemporaneous with this utterance'), "this must be because [the former] expresses something that cannot be expressed by anything like [the latter]." (p.833) But why should this matter? Perhaps the assumption is that sentences express world-involving propositions, so that the difference in expression reflects a difference in the world. But that would seem question-begging in this context. We might do better to skip straight to the question of how the world has to be in order to make our tensed sentences true. And, as noted here,

the sentences U: "The enemy is now approaching." and V: "The enemy [is] approaching simultaneously with U." are presumably made true by one and the same fact -- the tenseless fact of the enemy's approaching at some time t which is also U's time of utterance -- despite their lack of synonymity.

So the inference from language to reality seems thoroughly unmotivated. (Am I missing something?)

One way to bring this out is to consider the analogy between 'now' and other indexicals, e.g. 'I'. As Lewis and others have pointed out, there seems something special about attitudes de se, which refer to oneself under the indexical guise. They cannot simply be paraphrased into objective worldly descriptions. But I take it no-one is thus tempted to infer that the world itself contains a special property of "I-ness", held by me alone. So why does tensed talk tempt anyone into inferring that the world itself contains a special property of "presentness", held by the current moment alone?