Vertical uniformity of nature

One often talks of the “uniformity of nature” in the context of the problem of induction: the striking and prima facie puzzling fact that the laws of nature that hold in our local contexts also hold in non-local contexts.

That’s a “horizontal” uniformity of nature. But there is also a very interesting “vertical” uniformity of nature. This is a uniformity between the types of arrangements that occur at different levels like the microphysical, the chemical, the biological, the social, the geophysical and the astronomical. The uniformity is different from the horizontal one in that, as far as we know, there are no precisely formulable laws of nature that hold uniformly between levels. But there is still a less well defined uniformity whose sign is that same human methods of empirical investigation (“the scientific method”) work in all of them. Of course, these methods are modified: elegance plays a greater role in fundamental physics than in sociology, say. But they have something in common, if only that they are mere refinements of ordinary human common sense.

How much commonality is there? Maybe it’s like the commonality between novels. Novels come in different languages, cultural contexts and genres. They differ widely. But nonetheless to varying degrees we all have a capacity to get something out of all of them. And we can explain this vague commonality quite simply: all novels (that we know of) are produced by animals of the same species, participating to a significant degree in an interconnected culture.

Monotheism can provide an even more tightly-knit unity of cause that explains the vertical uniformity of nature—one entity caused all the levels. Polytheism can provide a looser unity of cause, much more like in the case of novels—perhaps different gods had different levels in nature delegated to them. Monotheism can do something similar, if need be, by positing angels to whom tasks are delegated, but I don’t know if there is a need. We know that one artist or author can produce a vast range of types of productions (think of a Michelangelo or an Asimov).

Any case, the kind of vague uniformity we get in the vertical dimension seems to fit well with agential explanations. It seems to me that a design argument for a metaphysical hypothesis like monotheism, polytheism or optimalism based on the vertical uniformity might not have some advantages over the more standard argument from the uniformity of the laws of nature. Or perhaps the two combined will provide the best argument.

Lying, acting and trust

A spy's message to his handler about troop movements is intercepted. The message is then changed to carry the false information that the infantry will be on the move without artillery support and sent onward. Did those who changed the message lie?

To lie, one must assert. But suppose the handler finds out about the change. Could she correctly say: "The counterintelligence operatives asserted to us that the infantry would be on the move without artillery support?" That just seems wrong. In fact, it seems similar to the oddity of attributing to an actor the speech of a character (though with the important difference that the actor does not typically speak to deceive). The point is easiest to see, perhaps, where there are first person pronouns. If part of the message says: "I will be at the old barn at 9 pm", it is surely false that the counterintelligence staff asserted they will be at the old barn (even though, quite possibly, they will--in order to capture the handler), but it also doesn't seem right to say that the counterintelligence staff asserted that the spy will be there.

The trust account of lying, defended by Jorge Garcia and others, seems to fit well with this judgment. On this account, to lie is to solicit trust while betraying it. But one can only betray a trust in oneself. The counterintelligence operatives, however, did not solicit the handler's trust in themselves: rather, they were relying on the handler's trust in the spy, and that trust the operatives cannot betray.

But there are some difficult edge cases. What if a counterintelligence operative dons a mask that makes him look just like the spy, and speaks falsehoods with a voice imitating the spy? But what if a spy goes to a foreign country with an entirely fictional identity? I am inclined to think that on the trust account the two cases are different. When one imitates the spy, one relies on the faith and credit that the spy has, and one isn't soliciting trust for oneself. When one dresses up as someone who doesn't exist, I think one is trying to gain faith and credit for oneself, and it seems one is lying. But I am not sure where the line is to be drawn.

Justice and the afterlife

1. If there is no afterlife, then promoting justice sometimes requires acting unjustly.

2. Promoting justice never requires acting unjustly.

3. So, there is an afterlife.

In support of 1, just think of cases where it looks like great injustices can only be stopped by minor injustices. Perhaps the only way to get an unjust dictator out of power is to spread the rumor that he is unfaithful to his wife. Perhaps the only way to bust a criminal organization is to have an informer make false promises. Of course, these cases presume that this life is all there is. If there is an afterlife, perhaps things are so arranged that all wrongs are righted in some way, so on the whole all will have justice. But without an afterlife, these cases are very compelling.

I think the weakness here is the "requires". There is a normative and a non-normative sense of "requires". Justice non-normatively requires A provided that justice cannot be had without A. Justice normatively requires A provided that in light of justice we are morally required to provide A. My line of thought above established claim 1 in the non-normative sense of requiring, whereas claim 2 is most plausible only in the normative sense of requiring.

Maybe. But I still think that 1 also has some plausibility with the normative sense of "requires" and 2 has some plausibility with the non-normative sense, so the argument as a whole has plausibility when "requires" is read consistently. The argument raises the probability of the conclusion. By how much, I do not know.

Being different at different times without changing

Here’s a curious thing: an unchanging object can have one shape at one time and a different shape at a different time.

Example 1: In the context of special relativity, times are spacelike hyperplanes. Suppose a special relativistic universe, and suppose that an object is an unchanging cube. Well, being a cube is not invariant between reference frames. So there will be one reference frame F₁ at which the object is an unchanging cube and another reference frame F₂ where it has some other unchanging shape. Each reference frame defines a family of times, i.e., spacelike hyperplanes. At the times of F₁, the object is cubical and at the times of F₂, the object is not cubical. Hence, at one time the object has one shape and at another it has another.

One might think that this example can be handled as follows: the object unchangingly is a cube-relative-to-F₁ and a non-cube-relative-to-F₂, and it is a cube-relative-to-F₁ even at the times of F₂ and a non-cube-relative-to-F₂ even at the times of F₁. But that’s probably mistaken. It seems to make no sense to talk of the shape-relative-to-F₁ at times in F₂. So we still have a difference in relative shape: the shape-relative-to-F₁ is well-defined at F₁ times but not well-defined at F₂ times.

Example 2: Different universes will have different spacetimes, and hence different times. Suppose an object that is wholly present simultaneously in multiple universes—after all, that seems no harder than multilocation within the universe, and we have some evidence of miracles where a saint is in more than one place at the same time (for an account of such possibilities, see this). In each universe the object is unchanging, but it has a different shape in different universes. Since the different universes come with different times, the object has one shape at one time and a different shape at a different time.

This seems to be a refutation of the at-at theory of change, on which change just is difference in properties across times. But while the cases, if possible, do indeed refute that theory, there is a slightly richer at-at theory that is unaffected by them:

• an object changes from having P to having Q provided that it has P and not Q at an earlier time and has Q and not P at a later time

• an object changes with respect to having a property P provided that it changes from having P to not having P or from having not-P to having P.

So it’s easy to fix the at-at theory. Still, I think something has been learned here: there is an essential directionality to change.

Change and intervals

Suppose a Newtonian universe where an elastic and perfectly round ball is dropped. At some point in time, the surface of the ball will no longer be spherical. If an object is F at one time and not F at another, while existing all the while, at least normally the object changes in respect of being F. I am not claiming that that is what change in respect of F is (as I said recently in a comment, I think there is more to change than that), but only that normally this is a necessary and sufficient condition for it. So the ball changes with respect to sphericity, and specifically changes from being spherical to being non-spherical.

When does the ball change from spherical to non-spherical? There are two kinds of times: times when the ball is still spherical and times when the ball is no longer spherical. At any time t at which the ball is no longer spherical it is already true that for some time the ball wasn’t spherical. Why? Well, whenever the ball isn’t spherical, it differs from sphericity by some non-zero amount, and it takes some time for the ball to deform by that amount. But if at a time t the ball had not been spherical for a while, then it’s not changing from being spherical to being non-spherical—rather, it had already changed.

What about times at which the ball is still spherical? These can be further subdivided into the pre-impact times and the time of impact. It’s clear that at the pre-impact times, the ball isn’t changing from being non-spherical to being spherical.

That leaves exactly one possible answer to the question of when the ball changes from being non-spherical to being spherical: at the time of impact. Now, at the time of impact, the ball is still spherical. We now have two interesting issues. The first is that if the future is open, there need be no fact of the matter at the time of impact that the ball will ever be anything but spherical (a powerful being could, for instance, make the ball penetrate the ground without changing shape). So if the future is open, it is not true at the time of impact that the ball is changing from spherical to non-spherical, since change with respect to sphericity requires being spherical and being non-spherical at different times. The second is that even if the future is closed, it seems awkward to say that at the time of impact the ball is changing with respect to sphericity. After all, the ball still is spherical then, and has been spherical for a while, and so it doesn’t seem right to say that something that is in the same state as it’s been for a while is changing with respect to that state.

So it seems that at no time is the ball changing from spherical to non-spherical. At any given time it either has already changed or it is going to change, but it never is changing.

What if time is necessarily discrete? That doesn’t change the arguments that the ball isn’t changing pre-impact or at the time of impact. But it allows for one more option: perhaps the ball counts as changing at the instant right after impact. On a discrete-time view, that is the first moment at which the ball is non-spherical. I am inclined to say: “No, the ball isn’t changing any more. It already has changed.”

Here’s a super-quick way of putting the above, neutrally between discrete and continuous time:

• When the ball is spherical, it will change but isn’t changing yet.

• When the ball is non-spherical, it has already changed but isn’t changing any more.

Since obviously we don’t want to deny that change happens, what should we say? I see two options. The first is to say that change is something that only makes sense from a four-dimensional perspective. To say that change happens is not to say anything about how the world is at a time, but how the world is at two or more times, just as to say that the road narrows at the 10 mile point isn’t really to say just what the road is like at the 10 mile point, but what it’s like before the 10 mile point and what it’s like after the 10 mile point.

But I think there is another option. Suppose that time is discrete, but that in addition to having instants it also has intervals between the instants. Then if t₁ is the instant of impact and t₂ is the next instant, there will be an interval I from t₁ to t₂. This interval is not like the intervals of mathematics—it isn’t a set of points of time between t₁ and t₂ inclusive, because on the theory in question there are only two points of time between t₁ and t₂ inclusive. Rather it is at least as fundamental as the instants themselves (and perhaps grounds the instants—but we don’t need that right now). Then we can say that the ball is changing from spherical to non-spherical at I.

On this story, we can say that change always happens at some time. But times include both instants and intervals. And change is something that doesn’t happen at an instant—that seems obvious when put that way—but something that happens at an interval.

But here is an interesting problem. It seems that for every time t at which the ball exists, either it is spherical at t or it’s not spherical at t. But what if t is the interval I? Then the ball is spherical at the beginning of the interval and non-spherical at its end. It seems it’s neither spherical nor non-spherical at I.

But that doesn’t follow. I think we can simply say that the ball is not spherical at I, because it’s not the case that it’s spherical throughout I. (A pipe that is square at some point in its length is not round.)

So we have come back to the idea that the ball changes from being non-spherical to being spherical at a time when it is already non-spherical. But that’s OK, because that time is an interval, and we cannot say that it is wholly non-spherical at that interval. It is non-spherical because it is partly non-spherical and partly spherical on that interval, because it is changing from spherical to non-spherical.

So, change happens at intervals. Or at least first-order change does. Second-order change, however, can be taken to occur at instants. Thus, if t₁ is the instant of impact and t₂ is the next instant and I₀ is the minimal interval just preceding t₁ while I₁ is the interval from t₁ to t₂ (which I previously just called I), then at I₀ the ball isn’t changing in sphericity, while at I₁ it is. And we can say that at t₁ it is changing from not changing in sphericity to changing in sphericity. Third-order change, then, will take place at intervals, fourth-order change at instants, and so on. There is no vicious regress: we just need two kinds of things, instants and intervals.

This is pretty complicated, more complicated than the simple story that change doesn’t happen at a time but at a pair (or more) of times. But it also gives me a nice story about what’s lacking in the at-at theory of change. It may be necessarily the case that an object changes if and only if it is one way at one time and another way at another time. But that isn’t what change is. What change is is having an interval of time such that the object is one way at one endpoint and another way at the other endpoint. But an interval is something over and beyond its endpoints. If, perhaps per impossibile, God were to annihilate the interval I between t₁ and t₂, the ball would be first spherical and then non-spherical, but it wouldn’t have changed from spherical to non-spherical.

Infinity, Causation and Paradox

I've just signed a contract with Oxford for this book, with a manuscript delivery date in September.

Analogue jitter in motivations and the randomness objection to libertarianism

All analogue devices jitter on a small time-scale. The jitter is for all practical purposes random, even if the system is deterministic.

Suppose now that compatibilism is true and we have a free agent who is determined to always choose what she is most strongly motivated towards. Now suppose a Buridan’s ass situation, where the motivations for two alternatives are balanced, but where the motivations were acquired in the normal way human motivations are, where there is an absence of constraint, etc.

Because of analogue jitter in the brain, sometimes one motivation will be slightly stronger and sometimes the other will be. Thus which way the agent will choose will be determined by the state of the jitter at the time of the choice. And that’s for all practical purposes random.

Either in such cases there is freedom or there is not. If there is no freedom in such cases, then the compatibilist has to say that people whose choices are sufficiently torn are not responsible for their choices. That is highly counterintuitive.

The compatibilist’s better option is to say that there can still be freedom in such cases. It’s a bit inaccurate to say that the choice is determined by the jitter. For it’s only because the rough values of the strengths of the motivations are as they are that the jitter in their exact strength is relevant. The rough values of the strengths of the motivations are explanatorily relevant, regardless of which way the choice goes. The compatibilist should say that this kind of explanatory relevance is sufficient for freedom.

But if she says this, then she must abandon the randomness objection against libertarianism.

Spiritual but not religious

A lot of people identify as spiritual but not religious. It would be interesting to have statistics on how common this is among professional philosophers. There are lots of naturalists and a significant minority of theists of definite religion, but I just haven’t run across many in between. But shouldn’t one expect that there be a lot of philosophers like that, convinced by argument or just intuition that there is much more to the world than science could possibly get at, but not convinced by the arguments for any particular religion? Maybe it’s because as a profession we prefer definite views? Or maybe there are many philosophers in this category but they just don’t talk about it that much?

I do think it’s important not to downplay the intellectual bona fides of the “spiritual but not religious”. The arguments that there is more to the world and to life than there is room for in naturalism, that there is something “spiritual”, are very strong indeed. (Josh Rasmussen’s and my forthcoming Necessary Existence is relevant here, as are considerations about the meaning of life, the narrow space for normativity and mind on naturalist views, the implausibility of holding that there be a whole category of human experience that is never veridical, etc.) I think there are strong arguments that this something “spiritual” includes God, and there are strong arguments that Catholic Christianity is correct. But it should be very easy to imagine being convinced by the arguments for a spiritual depth to the world but not being convinced by the further arguments (I am not taking a stance in this post on whether it would be rational full stop to be in this position—I do, after all, think the arguments going all the way to Catholicism are strong).

Epicurus on death

There is the classic Epicurean argument that:

1. You aren’t harmed by death when dead, since then you don’t exist, and

2. You aren’t harmed by death when alive, since then you’re still alive,

so:

3. You aren’t ever harmed by death.

I just thought of a cute way to make the argument slightly more compelling. Take it, contrary to fact but in accord with what the Epicureans believed, that death is the permanent cessation of existence.

Now let’s imagine a scenario where everything, including time itself, comes to an end at the last moment of your life. And for simplicity (this doesn’t affect anything) let’s suppose you came into existence at the beginning of time. Then you are never dead. When we think about this scenario, the analogue of claim 1 is trivially true, for you’re never dead. Thus on this scenario, all that needs to be thought about is an analogue of of claim 2 (with “death” being understood not as an event but as the fact that one’s life has an end) plus the additional highly plausible claim:

4. The scenario where everything, including time, comes to an end at the last moment of your life is no better for you than the scenario where you alone come to an end then.

I don’t think this makes the argument much more compelling, because I don’t think claim 1 was ever the real problem with the Epicurean argument. But in the scenario where time comes to an end, I think we avoid some irrelevant objections to the argument.

The real problem with the Epicurean argument is, I think, two-fold. First, I think 2 is dubious: your well-being at one time can depend on what happens or does not happen at other times.

Second, one can accept 3 and still think you’re harmed by death. For one can hold that one isn’t ever harmed by death, i.e., that there is no time at which one is harmed by death, but nonetheless as a four-dimensional whole one is worse off for death. Here’s one way to make the point. Suppose that by choosing a medical regimen for you, I can choose whether:

• You are unconscious for ten years, and then you live ten years while experiencing two units of wholesome pleasure each day, without anything negative, and then you cease to exist.
• You live ten years while experiencing one unit of wholesome pleasure each day, without anything negative, and then you cease to exist.

If I choose the regimen that gives you the second life, I harm you overall but you aren’t ever harmed—there is no time at which you’re worse off for that option.

Maps from desires and beliefs to actions

On a naive Humean picture of action, we have beliefs and desires and together these yield our actions.

But how do beliefs and desires yield beliefs? There are many (abstractly speaking, infinitely many, but perhaps only a finite subset is physically possible for us) maps from beliefs and desires to actions. Some of these maps might undercut essential functional characteristics of desires—thus, perhaps, it is impossible to have an agent that minimizes the satisfaction of her desires. But even when we add some reasonable restrictions, such as that agents be more likely to choose actions that are more likely to further the content of their desires, there will still be infinitely many maps available. For instance, an agent might always act on the strongest salient desire while another agent might randomly choose from among the salient desires with weights proportional to the strengths—and in between these two extremes, there are many options (infinitely many, speaking abstractly). Likewise, there are many ways that an agent could approach future change in her desires: allow future desires to override present ones, allow present desires to override future ones, balance the two in a plethora of ways (e.g., weighting a desire by the time-integral of its strength, or perhaps doing so after multiplying by a future-discount function), etc.

One could, I suppose, posit an overridingly strong desire to act according to one particular map from beliefs and desires to actions. But that is psychologically implausible. Most people aren’t reflective enough to have such a desire. And even if one had such a desire, it would be unlikely to in fact have strength sufficient to override all first-order desires—rare (and probably silly!) is the person who wouldn’t be willing to make a slight adjustment to how she chooses between desires in order to avoid great torture.

Nor will it help to move from desires to motivational structures like preferences or utility assignments. For instance, the different approaches towards risk and future change in motivational structure will still provide an infinity of maps from beliefs (or, more generally, representational structures) and motivational structures to actions.

Here’s one move that can be made: Each of us in fact acts according to some “governing mapping” from motivational and representational structures to actions (or, better, probabilities of actions, if we drop Hume’s determinism as we should). We can then extend the concept of motivational structure to include such a highest level mapping. Thus, perhaps, our motivational structure consists of two things: an assignment of utilities and a mapping from motivational and representational structures to actions.

But at this point the bold Humean claim that beliefs are impotent to cause action becomes close to trivial. For of course everybody will agree that we all implement some mapping from motivational and representational structures to actions or action probabilities (maybe not numerical ones), and if this mapping itself counts as part of the motivational structure, then everyone will agree that we all have a motivational structure essential to all of our actions. A naive cognitivist, for instance, can say that the governing mapping is one which assigns to each motivational and representational structure pair the action that is represented as most likely to be right (yes, this mapping doesn’t depend on the specific contents of the motivational structure).

Perhaps, though, a Humean can at least maintain a bold claim that motivational structures are not subject to rational evaluation. But if she does that, then the only way she can evaluate the rationality of action is by the action’s fit to the motivational and representational structures. But if the motivational structures include the actually implemented governing mapping, then every action an agent performs fits the structures. Hence the Humean who accepts the actual governing mapping as part of the motivational structure has to say that all actions are rational. And that’s a bridge too far.

Of course a non-Humean also has to give an account of the plurality of ways in which motivational and representational structures can be mapped onto actions. And if the claim that there is an actually implemented governing mapping is close to trivial, as I argued, then the non-Humean probably has to accept it, too. But she has at least one option not available to the Humean. She can, for instance, hold that motivational structures are subject to rational evaluation, and hence that there are rational constraints—maybe even to the point of determining a unique answer—on what the governing mapping should be like.

Looping and eternal pleasure

Scenario 1: You experience a day of deeply meaningful bliss and then are annihilated.

Scenario 2: You experience a day of deeply meaningful bliss and then travel back in time, with memories reset, to restart that very same day of an internally looping life.

Scenario 3: You experience a day of deeply meaningful bliss, over and over infinitely many times, with memories reset.

Here are some initial intuitions I have:

1. Scenario 3 is much better than Scenario 1.

2. Scenario 3 is at most a little better than Scenario 2.

But the following can be argued for:

3. Scenario 2 is no better than Scenario 1.

After all, you experience exactly the same period of bliss in Scenarios 1 and 2. Granted, in Scenario 1 you are annihilated, but (a) that doesn’t hurt, and (b) the only harm from the annihilation is that your existence is limited to a single day, which is also the case in Scenario 2. Time travel is admittedly cool, but because of the memory reset in Scenario 2, you don’t get the satisfaction of knowing you’re a time-traveler.

This is a paradox. How to get out of it? I see two options:

4. Deny the possibility of internal time loops.

5. Affirm that Scenario 3 is much better than Scenario 2.

Regarding 4, one would also have to deny the possibility of external time loops. After all, it wouldn’t be significantly all that different for you if everybody’s time looped together in the same way, and so external time loops can be used to construct a variant on Scenario 2.

I personally like both 4 and 5.

Objection: On psychological theories of personal identity, memory reset is death and hence in Scenario 3 you only live one day.

Response 1: Psychological theories of personal identity are false.

Response 2: Modify Scenario 3. Before that day of bliss, you have a completely neutral day. On each of the days of deeply meaningful bliss, you remember that neutral day, but then have amnesia with respect to the last 24-hour period once each blissful day ends. By psychological theories, there is identity between the person on each blissful day and the neutral day, and hence by symmetry and transitivity of identity, there is identity between the person over all the blissful days.

Note: Scenario 1 is inspired by a question by user “Red”.

Eternal pleasure

Suppose the minute of the greatest earthly pleasure you’ve ever tasted was repeated, over and over, for eternity, with your memory reset before each repeat. If hedonism were true, this would be a truly wonderful life, much better than your actual life. But it seems to be a pretty rotten life. So hedonism seems quite far from the truth.

But could there, perhaps, be a pleasure such that eternal repetition of it, in and of itself, would be worth having? It would have to be a pleasure that carries its meaningfulness in itself, one whose quale itself is deeply meaningful. It would have to have be an experience of infinite depth. Could we have such an experience? With Aquinas, I think philosophy cannot answer this question, though theology can.

Humean views of rationality and the pursuit of money

Consider a Humean package view of rationality where:

1. Then end of practical rationality is desire satisfaction.

2. All the rational motivational drive in our decisions comes from our desires.

3. There are no rational imperatives to have desires.

Now suppose that you learn that some costless action will further one or more of your desires, but you have no idea which desire or desires will be furthered by that action. (If we want to have some ideality constraints on which desires make action rational—say, only desires that would survive idealized psychotherapy—then we can suppose that you also know that the desire or desires furthered by the action will satisfy those constraints. I will ignore this wrinkle.)

Any theory of rationality that holds it to be rational to pursue one’s desires should hold it both rational and possible to take that costless action. In the abstract, a case where you know that some desire will be furthered but have no idea which one seems a strange edge case. But actually there is nothing all that strange about this. When money is offered to us, sometimes we have a clear picture of what the money would allow us to do. But sometimes we don’t: we just know that the money will help further some end or other. (Of course, in some people, the pursuit of money may have a non-instrumental dimension, but that’s vicious and surely unnecessary.)

So now let’s go back to the costless action that furthers one or more of your desires and the desire theory of rational motivation. How can this theory accommodate this action?

Option 1: Particular desires. You pick some desire of yours—let’s say, a desire to read a good book—and you think to yourself: “There is a non-zero probability that the action furthers my desire to read a good book.” Then the desire to read a good book, in the usual end-to-means ways, motivates you to do the costless action.

That, of course, could work. And in fact, in the case of money we do sometimes proceed by imagining something that we could buy. However, thinking that what motivates one is just the non-zero probability of furthering a particular desire gets things wrong for two reasons. The first is that we could imagine the case being enriched by your learning that the desire that will be furthered by the action is none of the desires that would come to mind if you were to spend less than a minute thinking about the case but that you need to make your decision within a minute. The inability to think of a particular desire that even might be furthered by the action does not affect the ratioanl possibility of taking the costless action.

The second is that this approach gets the strength of motivation wrong. You have many desires, and the desire to read a good book is only one among many. The probability that that desire to read a good book would be furthered by the costless action might well be tiny, especially if you received the further information that it is only one of your desires that is furthered by the action. Such a small probability of a benefit could still motivate you to take a costless action, but it may not work for similar cases where there is a modest cost. For instance, we can suppose you learn that:

4. The benefit is roughly equal to reading a good book as measured by desire-satisfaction.

5. The cost is roughly equal to a tenth of the benefit of reading a good book as measured by desire-satisfaction.

6. You have a hundred desires and the one furthered is but one of them.

Well, then, the action is clearly worth it by (4) and (5). But it’s not worth doing the action simply on a one percent chance that it will lead to reading a good book, since the cost is ten percent of the benefit of reading a good book.

One might try to remedy the second problem by mentally going through a larger number of desires so as to increase the probability that some one of the desires will be fulfilled. But we still have the first objection—there may not be enough time to do this—and surely it is implausible that one would have to go through such mental lists of desires in order to get the motivation.

Option 2: A higher-order desire to have satisfied desires. Suppose you have a higher-order desire H to satisfy lower-order desires. Then while you don’t know which lower-order desire is furthered by the action, you do know that this higher-order desire is furthered by them.

This approach seems to lead to an unfortunate double-counting. When you sit down to read a good book, do you really get two benefits, one of reading the book and the other of furthering the higher-order desire to have satisfied lower-order desires? If not, the approach is problematic. But if so, then it gets the rational strength of motivation wrong. For suppose that you are choosing between two actions. Action A will lead to your reading a good book. Action B will lead to the fulfillment of an unknown desire other than reading a good book, a desire you nonetheless know to have the same weight. On the higher-order solution, it seems you have a double motivation for action A, namely H and the desire to read a good book, but only a single motivation for action B, namely H, and hence you should have a twice as strong rational motivation for A. But that’s surely not rational!

Maybe, though, you can get out of the double-counting in some way, by having some story about desire-overlap, so that H and the desire to read a good book don’t add up to a double desire. I suspect that this may undercut the force of the story, by making H not be a real desire.

But there is a second and more serious problem with the story. Suppose that Jim has all the usual lower-order order desires but lacks H. If rational motivation comes from desires, then Jim will not be rationally motivated to the action. (Maybe he will have some accidental non-rational motivation for the action.) But surely not going for a costless action that he knows will fulfill some desire of his will be a rational failing, assuming that it’s rational to fulfill one’s desires. Hence there will have to be a rational imperative to have H among one’s desires, contrary to the third part of the Humean package we are exploring.

Now I suppose we could drop the third part of the Humean picture, and hold that rationality requires some desires like H. But I think this makes the rest of the picture less plausible. If rationality requires one to have certain desires, it could just as well require one directly to fulfill certain ends, thereby undercutting the second part of the Humean picture.

Finally, I should note that not all non-Humeans should rejoice at this argument. For similar considerations may apply against some other views. For instance, some Natural Law views that tie motivation very tightly to basic goods may have this problem.

Necessary Existence

Josh Rasmussen's and my Necessary Existence book is now complete. We just sent the final manuscript to Oxford. We're both quite happy with the book.

Freezing a hard drive

I had a hard drive that's around 15 years old fail to start a couple of months ago--I tried many times with no luck. Most but not all of the stuff was backed up, but not all (though what wasn't backed up wasn't very important). So yesterday I stuck the drive in a freezer, in two freezer bags without much air. Today I plugged it into an IDE-USB adapter. It didn't start up at first, but after a few minutes of warming it up, it started and I got all the data off without any difficulty.  This is the second time in my life that I've rescued data from an old hard drive using a freezer.

(Of course, there is always the chance that this time it would have worked without the freezer. I didn't actually check yesterday if the drive was still not working.)