Reasons Why

Interview by Richard Marshall.

'I think the idea that time doesn't pass in the block universe theory comes from the commonly-made claim that according to that theory "reality as a whole does not change." After all, if reality does not change, time does not pass, since the passage of time must be some kind of change---presumably, a change time itself undergoes. I think, however, that it is at best misleading to say that according to the theory reality as a whole does not change.'

'The stellar collapse example goes something like this: a star is collapsing, and then stops; it does not collapse "all the way" into a black hole. The question is why it stopped collapsing. Railton and Lewis thought the answer was something like: because there were no "more collapsed states" for the star to get into. They thought that this followed from the Pauli Exclusion Principle (which says that no two identical fermions---for example, no two electrons---can be in the same quantum state).'

'If all I want is for my life not to go well, then if I get what I want my life is not going well, in which case (according to the theory) I am not getting what I want, which is a contradiction. You also get a contradiction on the assumption that I do not get what I want.'

Brad Skowhas research interests in the philosophy of physics, the philosophy of science, metaphysics, and ethics. Here he discusses the block theory of time, the Moving Spotlight rival theory, how fast time passes, causal vs non-causal explanation, teleological answers to why questions, explanations of actions, the difference between understanding why and knowing why, Shelly Kagan and indeterminate desert, Haeccetism and why getting what you want when all you want is for your life not to go well can be untangled. Read these microhelen thoughts and launch your own drunken boat...

3:AM:What made you become a philosopher?

Bradford Skow:I arrived at Oberlin College intent on majoring in English literature. One thing that makes Oberlin great is that it doesn't have any required courses to get in the way of your pursuing your interests; so I'd pretty much wrapped up that major by the beginning of my third year. But all along I'd also been taking philosophy classes. My first year roommate had had an infectious excitement about the Existentialism course, which spread to me, but that course had prerequisites, so I took those prerequisites, and then just kept taking philosophy classes...ironically, I never ended up taking Existentialism. During my third year I started gravitating more toward philosophy than English. For one thing, I started losing my grip on what one was supposed to accomplish when writing an essay for an English class. Philosophy was different: ultimately, you're trying to answer a philosophical question (even if your proximate goal is to evaluate Descartes', or whomever's, proposed answer). Also, and I don't know how much this was part of my thinking at the time or was only a retroactive justification later, I decided that I didn't want to be a literary critic, because it was too parasitic: critics write about great works of literature but don't produce great works themselves (or at least, they don't in their capacity as critics). When you study philosophy, on the other hand, the writing you do *about* philosophy *is also philosophy*, so you have a shot at being in the same class as Plato or Hume (however unlikely it is that you'll make it).

3:AM:Let’s begin with your thoughts about time. You defend the block theory of timedon’t you. So to start with can you sketch what this theory says time is.

BS:I should preface my answer by saying that, as I've worked in the philosophy of time, I've come to believe that the differences between the competing views cannot easily be expressed in ordinary non-technical English. This makes the debates somewhat inaccessible to outsiders. So with that warning: the block universe theory of time is sometimes called the "tenseless" theory of time, and I think that's in part right, in this sense: the theory says that a description of what reality is like, at the most fundamental level, must be written in a tenseless language. (Since ordinary English is not a tenseless language, this description will, at the very least, use English words with meanings different from their ordinary ones.) One thing the theory says is that the past and the future _exist_ (where underlined verbs like this one are "tenseless"), that is, they really _are_ part of reality. In this respect the theory says that time is like space: just as Australia really exists, it is just in a part of reality that is spatially distant from us, the theory says that the past and future _exist_, they are just in parts of reality (or, better, they *are* parts of reality) that are *temporally* distant from us. Time is "just another dimension of reality" along with the three spatial dimensions. Then, the theory continues, all tensed talk, all talk about what was the case, and what will be the case, is made true by what reality is like, tenselessly speaking. So for example the tensed sentence "There were dinosaurs" is made true by the fact that there _are_ (again, speaking tenselessly) dinosaurs located in the past.

3:AM: It looks as if the idea of time flowing or passing doesn’t make sense with this conception. Why isn’t that quite right?

BS:I think the idea that time doesn't pass in the block universe theory comes from the commonly-made claim that according to that theory "reality as a whole does not change." After all, if reality does not change, time does not pass, since the passage of time must be some kind of change---presumably, a change time itself undergoes. I think, however, that it is at best misleading to say that according to the theory reality as a whole does not change. If you take "reality as a whole does not change" to entail, for example, "If there ever were dinosaurs, there will always be dinosaurs," then the theory does not say that reality as a whole does not change, because this consequence is false in the theory. The quoted sentence is a tensed sentence, and so has tenseless truth-conditions; in this case the theory says that "If there ever were dinosaurs, there will always be dinosaurs" is true if and only if, if there _are_ dinosaurs located in the past, then there _are_ dinosaurs located at every future time, which there are not. This highlights the fact that it is important, when discussing the Block Universe Theory, to keep clear when you are speaking in fundamental terms and when you are speaking in non-fundamental terms; when speaking in non-fundamental terms, the theory definitely says that time passes. I would certainly take it to be a huge defect in the theory if it required me to say that people waiting for the bus saying "Time sure is passing slowly today" were saying something false.

This obviously raises the question of whether "Reality as a whole does not change" (which is going proxy in this conversation for "time does not pass") is true in the theory when speaking in *fundamental* terms. The way I understand the theory, "Reality as a whole does not change" does not even *make sense* in fundamental terms---and if it does not make sense, it is not true. But I think that some opponents of the theory take this to be enough to make it appropriate to characterize the theory as one in which time does not pass.

3:AM:Although you say the block universe has an anemic passage of time you take very seriously the theory that has a robust notion of the passage of time, the spotlight theory, don’t you. So can you sketch for us what this strong opponent to the block theory claims and why you think it a stronger alternative to anemic theories than presentism?

BS:One standard version of The Moving Spotlight Theory says that the fundamental language for describing reality *is* a tensed language, and asserts the following in that language: exactly one time is present, each past time was present, and each future time will be present. And this verb-phrase "...is present" does not mean what Block Universe guys will try to tell you it means: they'll try to tell you that it is an indexical like "I," they will say that just as "I" refers to the speaker on any occasion of use, "...is present" applies to the time it is used on any occasion of use (or, maybe, that its meaning depends on the context of use in some more complicated way). Instead, on this theory "...is present" is not context-sensitive; sometimes this is put by saying that the time that is present is "objectively" present.

What I like about this theory, as an account of "robust" passage of time anyway, is that it says that time itself changes, because which time is "objectively" present changes. As for presentism---well, I don't want to spend too much time explaining all of these theories, and risk boring people, but the most straightforward version of presentism says that there is no such thing as time in the first place. Presentists don't deny that *tensed talk* makes sense, of course, they just deny that its making sense requires the existence of any such thing as time. Now a standard way to make sense of "time is passing," if you are a presentist, is to have it mean "something or other is changing"---that's pretty much what Arthur Prior, the ur-presentist, said it meant. Since presentism denies the existence of time, it follows that if no "ordinary things" are changing, then *nothing* is changing, and so time is not passing. If, in particular, there were only one thing, say a lonely electron, and it was sitting still, not moving, not changing in any way, then the presentist I am imagining has to say that time is not passing. But insofar as I have a grasp on what "robust" passage of time is, it is something that should be able to happen even if there is just one electron and it never changes. The phenomenon that The Moving Spotlight Theory identifies with the passage of time---the change in which time is present---*can* still happen in a lonely-electron world.

3:AM:Can the moving spotlight theory give a coherent answer to the question of how fast time passes?

BS:*I* think it can. The question of how fast time is passing is, on this theory, the question of how fast "presentness" is moving, and you answer this question in the same way you answer the question of how fast a plane, or a train, is moving: divide the distance traveled by the time of the trip. The only difference is that, while planes travel trough space, "presentness" is traveling through time itself. So to compute the average rate at which time is passing just do this: (i) figure out which time N is "objectively" present; (ii) find the time time M such that M will be present in 1 second; find the "temporal distance" S in seconds between M and N; then time is passing at S seconds per second. Presumably S will equal 1, so the theory will say that time is passing at 1 second per second.

Some philosophers have argued that something must be going wrong here, on the ground that 1 second per second is not a rate, but they must be mistaken. The period of a pendulum, for example, the time it takes to complete a full swing, is measured in seconds, and also depends on the length of the pendulum. If you're taking an exam in Physics 101 and the test says "a pendulum is growing in length at a rate BLAH; at what rate is its period changing?", and you do the calculations, and you get the answer that it's changing at 1 second per second, you'd be in big trouble if you thought "that can't be right, 1 second per second isn't a rate." You'd be in bigger trouble, and give philosophy a bad name, if you went and complained to your Nobel-prize winning professor that he can't mark you off for not answering because some philosophers had shown his question to be meaningless.

3:AM:Why do you ultimately reject the spotlight theory and choose the block universe approach – is it because it better accords with our experiences?

BS:Well...it might be that the reasons in favor of the block universe theory that are decisive for me are not the ones I spend the most time on in my writing on the topic. I probably ultimately reject the spotlight theory on the ground that the block universe theory fits better with what physics teaches us about time. But I don't think I could win an argument about this with a devout defender of the spotlight theory (where to win your opponent must come to agree with you).

I do think that the strongest argument against the block universe theory is that it leaves something out, something (a feature of time) that we are made aware of just by opening our eyes (or ears) and looking around. But I also think that there is nothing to this argument: there is nothing about what one might call "our experience as of time passing" that cannot be accounted for by the block universe theory.

3:AM:Your second bookexamines what we’re after when we ask for an explanation. So you offer a theory of reasons why that disputes any idea that there might be non-causal explanations answering the question. Can you first sketch for us the accounts of non-causal explanation that you are disputing such as Nerlich’s examples of geometrical explanation or Railton/Lewis’s stellar collapse?

BS:The stellar collapse example goes something like this: a star is collapsing, and then stops; it does not collapse "all the way" into a black hole. The question is why it stopped collapsing. Railton and Lewis thought the answer was something like: because there were no "more collapsed states" for the star to get into. They thought that this followed from the Pauli Exclusion Principle (which says that no two identical fermions---for example, no two electrons---can be in the same quantum state). Railton thought he had found an answer to our why-question that doesn't say anything about the causes of the stopping; so he thought he had found a "non-causal" explanation.

3:AM:Why don’t these serve as counter-example to your account?

BS:Well, to answer I first need to say a bit about my theory. The ten-second background is that I think a theory of explanation---what philosophers want out of a theory of explanation---is a theory of answers to why-questions. And I think we would all be better off if we banned the word "explanation" from philosophical writing on explanation, and instead always spoke about why-questions and their answers. I think that that word creates too many opportunities for confusion.

I also think that the first step toward a theory of answers to why-questions is easy: the complete answer to the question of why Q (say, why the window broke) looks like this: one reason why Q is that R1, another reason why Q is that R2, ... (Actually, this applies only to "non-teleological" why-questions.) The hard part, for a philosopher anyway, of a theory of answers to why-questions is to says what it takes for something to be a reason why Q. My view in the book (I've actually had some second thoughts about some aspects of the view) is that something is a reason why Q if and only if it is either a cause, or a ground, of the fact that Q ("ground" in the metaphysicians' sense, where to say that one fact grounds another is to say that the first fact is the more fundamental fact in virtue of which the second obtains; so for example the fact that such-and-such neurons are firing in my brain grounds the fact that I have a mild headache).

It is easy to find "confirming instances" of the theory: a bomb explodes, causing a window to break; sure enough, it is also true that one reason why the window broke is that the bomb exploded. One reason why the economy collapsed in 2008 was that banks were giving mortgages to people who couldn't afford to pay; sure enough, those bank activities were also a cause of the collapse.

So what about the stellar collapse example? Is it a counterexample? If it were in fact true that one reason why the star stopped collapsing was that there were no "more collapsed states" for it to get in to, then it would be a counterexample to my theory, because the fact that there were no more collapsed states is certainly not a cause (or a ground) of the stopping. But Railton had his physics wrong; if you open up an undergraduate textbook on thermodynamics, it will tell you that stellar collapse is (of course) driven by gravity, and that when a star stops collapsing, the reason why it stops is that something called "electron degeneracy pressure," which is directed outward, and so opposes the inward force of gravity, has become equal in strength to the force of gravity. And this reason, an increase in the magnitude of a certain force, is certainly a cause of the stopping.

3:AM:How do you approach teleological answers to why questions?

BS:A teleological answer to the question why Q is something that can be put in the form: Q in order to V. A canonical example is that "The chicken crossed the road in order to get to the other side" is an answer to "Why did the chicken cross the road?"

I favor a "causal reduction" of teleological answers to why-questions. What would it take for it to be true that this rock is moving down in order to get to the center of the universe? The idea is that its moving down would have to have certain causes. What causes? The short version of the theory in *Reasons Why* is that *the fact that moving down was a way to get to the center of the universe* would have to be a cause. The biggest problem I see for this theory is skepticism about whether a fact like that *could* cause anything. (For I don't want to reach the conclusion that it is it *impossible* that a rock move down in order to get to the center.) I've fallen more into the grip of this skepticism than I was when I wrote the book, and am still trying to figure out how to put it to rest (if indeed it can be).

3:AM:And what do you say about answers to why questions that give an agent’s reasons for acting?

BS:Right, so some why-questions are ambiguous: if Joan is driving her car and an evil demon has implanted electrodes in her brain allowing him to control her motions, and he causes her to turn left, there is a reading of "Why did Joan turn left?" where "because the demon pressed button L" is an answer, but there's another reading where it is not, where you reject the question altogether, by saying something like "what do you mean? she didn't do it on purpose." This second reading is the reading where the why-question requests Joan's reason(s) for turning left. If you do something for a reason, you do it intentionally (or on purpose); so, conversely, if you don't do something on purpose, you don't do it for a reason, and the question of why you did it, interpreted as a request for those reasons, does not even arise.

The main philosophical question about reasons for action is: what is it for a proposition to be someone's reason for acting, on a given occasion? I don't have a new theory of reasons for acting to offer, though I am sympathetic with so-called "causal" theories of reasons for acting (that P is X's reason for Zing iff X's Zing had certain kinds of causes, causes obviously connected in some way with the fact that P). My main thought about reason for acting as answers to why-questions is that the correct theory of them, whatever it is, will need to invoke a distinction between "levels of reasons" that I make use of a lot in defending my theory.

The distinction is between the reasons why something happened, on the one hand, and the reasons why those reasons are reasons, on the other. So if I strike a match and thereby cause it to light, that I struck it is a reason why it lit, and that the room had oxygen in it was a reason why that reason was a reason. So that's an example that illustrates the difference. I think that these two levels are distinct: if X is a reason why R is a reason why Q, it does not follow that X is a reason why Q. A lot of theorizing about explanation (oops, I mean answers to why-questions) has gone wrong by assuming that this does follow. Anyway, I think that the correct theory of reasons for action will need to attend, not just to the reasons why the person acted as they did (where here "reason why" does not mean "reason for which"), but also to the reasons why those reasons are reasons.

3:AM:Why isn’t saying simply that ‘explanation is that which produces understanding’ any good as a theory of explanation? Isn’t this what someone like Elliott Sober might argue for?

BS:A lot of philosophers have said that explanation is that which produces understanding. It's a refrain that has been repeated at least since Hempel asserted it in 1965. I think this is a perfect example of how the word "explanation" can cause confusion. If you try to make precise what the claim here is, you get something like: if someone knows why Q, then they understand why Q. If someone knows why that star went supernova, then they understand why that star went supernova. And I think that is plainly false. Understanding why Q is a greater cognitive achievement, I think, than knowing why Q.

3:AM:If one ought to give people what they deserve, and what one deserve depends on whether one does what one ought, then paradox and indeterminacy threaten. How do you solve the problem of indeterminate desert?

BS:Shelly Kagan, a philosopher at Yale, discovered the problem of indeterminate desert. These two ideas are fairly plausible: (i) you ought to give people what they deserve; and (ii) people who do what they ought to deserve to have good things happen to them. But if we also accept the *converses* of these ideas (the only thing you ought to do is give people what they deserve, the only people who deserve to have good things happen to them are those who do what they ought) they generate paradoxical situations: suppose there are just two people, X and Y; X does something that benefits Y (so in doing it something good happens to Y); Y does something that benefits X. We know now what X and Y got; but did they get what they deserve? You might think that the answer should be contained in what we've already said about the example. But it is not. We could consistently add to the story that they did get what they deserve: if each deserved a benefit, then since each gave a benefit, by (i) each did what they ought to, and so by (ii) each deserved a benefit; there's no contradiction. But there is also no contradiction in assuming that they did not get what they deserve: if neither deserved a benefit, then since each gave a benefit, by (i) neither did what they ought to, and so by (ii) neither deserved a benefit---again no contradiction.

Kagan's aim was more ambitious than that of pointing out that (i) and (ii) and their converses lead to paradox; he thought also that any plausible weaker view suffered from the same problem. For example, you might wonder: what if you hold on to (i) but reject its converse, saying that you have other obligations besides giving people what they deserve? Same problem arises, Kagan argued. I think Kagan was wrong about that, and tried to show (in fact prove) he was wrong using a bit of mathematics.

I worked on this topic at a time when I believed that mathematics was an under-appreciated tool for solving philosophical problems and making philosophical progress. I was going to show the world just how under-appreciated it was. Looking back, this may seem like a strange attitude: hasn't analytic philosophy over the last 100 years or so placed great (too much?) weight on mathematics as a tool? It certainly has placed great weight on formal logic as a tool, but I thought it was ignoring other branches of mathematics that could also be useful. Think how much progress we could make if the Contraction Mapping Theorem were more widely-known!

I've since abandoned this particular research program, though I'm not sure whether it's because I am not as confident as I was about its prospects, or because I just realized that I'm not the guy to carry it out.

3:AM:You’ve argued that David Lewis was the opposite of what he claimed when it came to the issue of Haeccetism! So can you sketch what this h word is about and why Lewis wrong self assigned?

BS:This is just a case where I thought that the way Lewis was using the terminology was causing confusion. I'll start by saying what haecceitism is (at least as I understand it). It is actually easier to first explain the opposing view. One standard way to understand *anti*-haecceitism makes it this thesis: necessarily, things couldn't have been different, "non-qualitatively speaking," without being different, "qualitatively speaking," where you are "speaking qualitatively" if you are using language that does not refer to any particular individuals. "There are three red things" is a qualitative statement, on this definition, while "This ball is red" is not. So could history have gone exactly the way it actually did, qualitatively speaking, except that me and my eldest brother "switched qualitative roles": he looked as I do, I looked as he did, he was born first, I was born second, etc, etc? Anti-haecceitism says no. The most liberal form of haecceitism, on the other hand, says yes. Now David Lewis agreed that my brother and I could have switched qualitative roles; he says what the haecceitist (as I've characterized the view) says. But he *called* himself an anti-haecceitist.

Let's call modal statements couched in ordinary modal vocabulary "first-order modal statements." So "My brother and I could have switched qualitative roles" is an ordinary modal statement (I know, not quite the ordinary sense of "ordinary"). And let's call modal statements that use the "apparatus of possible worlds" "extraordinary" modal statements. What's going on is that haecceitism and anti-haecceitism, as I have defined them, and I think as they have traditionally been understood, are theses about which ordinary modal statements are true. Not so for Lewis; for him, they are theses about the truth of certain extraordinary modal statements. He held haecceitism to be the thesis that there are possible worlds W1 and W2 that are qualitative duplicates, and an individual X, such that what is possible for X according to W1 differs from what is possible for X according to W2. It's a pretty complicated definition. Anyway, Lewis goes on to show---he doesn't put it this way, of course---that haecceitism, in the sense I gave, is compatible with anti-haecceitism, on his definition. "BAS's and his brother could have swapped qualitative roles" is true, Lewis says, but its truth doesn't require that there be two qualitatively identical worlds that differ in what they say is possible for me and my brother. Lewis said and many after took him to have shown that he had found a way to be an anti-haecceitist while "being able to say" the sorts of things haecceitists want to say. But really what's going on is that he invented a new sense of "anti-haecceitism" so that the new view he attached that name to was consistent with haecceitism (in what I take to be its original sense).

3:AM:If I don’t want my life to go well then the theory that my life goes well to the extent that I get what I want seems inconsistent. Why don’t you agree?

BS:The problem is supposed to be: if all I want is for my life not to go well, then if I get what I want my life is not going well, in which case (according to the theory) I am not getting what I want, which is a contradiction. You also get a contradiction on the assumption that I do not get what I want. My suggestion was that there are more options besides "getting what you want" and "not getting what you want"; there is also "getting what you want to degree r," where r is some number between 0 and 1. The derivation of the contradiction no longer works now, and I also think you can show directly that the theory is consistent. On plausible assumptions, in fact, your life is going neither well nor not-well, and you are getting what you want to degree 1/2. (If the *Journal of Mathematical Ethics* had ever been founded in reality, I would have wanted this paper to appear in it, even if it doesn't measure up to the proposal to define the "microhelen" as "the amount of beauty needed to launch one ship.")

3:AM:And finally are there five books other than your own that you can recommend to the readers here at 3:AM to take us further into your philosophical world?

Fred Feldman, *Pleasure and the Good Life.* There is often a trade-off in philosophy between how clear the arguments are and how many creative insights there are. Not in Fred's work; this is my favorite of his books.

Gordon Belot, *Geometric Possibility.* A great example of mathematical sophistication fueling philosophical creativity. For example, Gordon uses a mathematical precisification of the common idea that "logical space has no gaps" to reach a surprising conclusion. And the math/creativity virtue is just one of the philosophical virtues that the book displays.

Peter van Inwagen, *Material Beings*. The book that made me fall in love with metaphysics. Until I read it (this was before graduate school), it seemed to me that metaphysicians were only interested in addressing questions about esoteric things like possible worlds, things only philosophers had even heard of and that surely they'd just made up anyway. Van Inwagen takes up instead the question of whether there are really any tables and chairs---a question about things that ordinary people had (or thought they had) some acquaintance with. I thought then that it showed metaphysics to be relevant to people's lives in a way that the possible worlds debates weren't. That was probably a mistake.

Arthur Prior, *Papers on Time and Tense.* Taken as a whole this is not a great book, but it contains one of the top five philosophy papers of all time---"Changes in Events and Changes in Things"---and Prior is one of the greatest prose stylists philosophy has ever had.

Janet Malcolm, *In the Freud Archives*. Malcolm is not a philosopher, but I want to write philosophy the way she would if she were.

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