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Causes, Laws, and Free Will: Why Determinism Doesn't Matter

 

I have finished my book Causes, Laws, and Free Will:  Why Determinism Doesn't Matter and it is now "in production", as they say, at OUP.  Since I have been writing it for what feels like several centuries, I am much relieved. 

The cover art will be A Game of Chess  by  Sofonisba Anguissola, which I have always loved.

It will be published sometime next year.  

Here is the abstract:

Introduction

Common sense says that we are morally responsible for our actions only if we have free will and that we have free will only if we are able to choose among  alternative actions.  Common sense says that we do have free will and are morally responsible for many of the things we do. Common sense also tells us that we are objects in the natural world, governed by its laws.  And yet  many contemporary philosophers deny that we have free will or that free will is necessary for moral responsibility.  Some hold that we are morally responsible only if we are somehow exempt from the laws of nature.    Causes, Laws, and Free Will argues that this philosophical flight from common sense is a mistake.  We have free will and we are morally responsible whatever the laws of nature may turn out to be. The impulses that tempt us to think that determinism robs us of free will are mistakes --  mistakes about the metaphysics of causation, mistakes about the nature of laws, and mistakes about the logic of counterfactuals.   

CHAPTER 1:   The Problem Introduced: Would Determinism Rob us of Free Will?

I introduce the Basic Argument:

1.  If determinism is true, we are never able to do otherwise.

2.  If we are never able to do otherwise, we have no free will.

3.  If we are never able to do otherwise, we are never morally responsible.

Therefore, if determinism is true, we have no free will and are never morally responsible.

I distinguish two kinds of compatibilists. Moral compatibilists concede or do not dispute the first premise; they reject the third premise.  Metaphysical compatibilists concede the second  premise, but reject the first premise.  This book will defend metaphysical compatibilism.  I distinguish determinism  from some claims about causes and laws.  I note an ambiguity in  'has the ability' and  'is able to'  and draw a distinction between narrow and wide abilities.  The metaphysical compatibilist rejects the first premise by arguing that determinism is compatible with both kinds of abilities.

CHAPTER 2: The Problem Distinguished:  Is it Possible for Us to Have Free Will?   Do We Have Free Will?

I distinguish three questions about free will.  Is it possible that we have free will?  Is it possible both that determinism is true and that we have free will?   Do we actually have free will?  We need to distinguish the impossibilist from the incompatibilist.  The impossibilist answers 'no' to the first question and thus 'no' to the other two questions.  The incompatibilist answers 'yes' to the first question and 'no' to the second question.  The metaphysical compatibilist answers 'yes' to the first two questions.  The common sense compatibilist answers 'yes' to all three questions and also says that determinism doesn't matter; that is, the common sense compatibilist says that free will is compatible with indeterminism as well as determinism. This book will defend common sense compatibilism.  I examine two kinds of arguments for impossibilism  -- the arguments of the logical fatalist and arguments that claim that  free will (or moral responsibility) requires a self-making ability that is impossible for any non-godlike creature.

CHAPTER 3:  Abilities, Choices, and Agent Causation

Our belief that we have free will, including the ability to do otherwise, is based on our many and varied experiences of reliably moving our minds and bodies in the ways we try to move them and our belief that we are always, or almost always, able to try.  I argue that these beliefs about our causal powers are neutral with respect to determinism and the details of the truth about the causal relation and causal relata.   Some philosophers argue that we are free and morally responsible agents only if determinism is false and we cause our choices or basic actions in some way that does not consist in event-causation; this is called 'Agent-causation'.  I investigate the metaphysics of Agent-causation and argue that insofar as we have reason to believe that Agent-causation is possible, we have reason to believe it is compatible with strict deterministic laws.

CHAPTER 4:  The Unavoidability of Metaphysics: Moral Responsibility and Ability to Do Otherwise

Frankfurt  famously defended moral compatibilism by arguing that,  no matter what your view of free will, you should agree that a person may be morally responsible for what she did even if she wasn't able to do or even choose or try or begin to do otherwise. His argument fails. There are two very different methods that a Frankfurt-style  intervener can use to ensure that his subject chooses and does only what he wants her to choose and do. The first method -- the method of the Bodyguard -- succeeds in limiting the subject's freedom,  but it does not and cannot rob the subject of her ability to choose or at least begin or try to choose otherwise. The second method -- the method of the Pre-Emptor -- is logically bogus.  I argue that it is a modal fallacy to think that the Pre-Emptive intervener in a Frankfurt story deprives his subject of any freedom or ability.

CHAPTER 5:   Arguments for Incompatibilism

The incompatibilist claims that at deterministic worlds a  necessary condition of free will (or moral responsibility) is always absent.   Arguments for this incompatibilist conclusion come in two varieties.  The first kind of argument is based on the premise that we have free will (or are morally responsible)  only if we are the "sources" (first causes, originators, Agent-causes) of our choices or basic actions.  The second kind of  argument is based on the premise that we have free will (or are morally responsible) only if we are at least sometime able to do (choose, try, or begin to do) otherwise.   I examine and reject both kinds of arguments.  The failure of the arguments is due to mistakes about the relation between laws, causation, counterfactuals, and our causal powers.  Peter van Inwagen claims that his Consequence argument has "raised the price" of compatibilism by making its metaphysical commitments clear.  I will argue that the price of compatibilism is less than the price of the incompatibilist alternative.

CHAPTER 6: The Abilities and Dispositions of our Freedom

I propose a determinism-neutral account of free will.   We have the free will common sense says we have by having some bundle of narrow abilities and by being in suitably friendly surroundings; when this is so, we have not only the narrow but also the wide ability to do otherwise.  I call this 'the Bundle view'. We have narrow abilities by having dispositions with an intrinsic causal basis; we have wide abilities when the relevant dispositions are not finked, masked, or lacking an extrinsic enabler.  I defend a modified version of Lewis's analysis of dispositions, but the Bundle view is not committed to the truth of any particular analysis.  I use the Bundle view to provide a diagnosis of the failure of Frankurt's argument and the Consequence argument. I argue that the objections that defeated the Simple Conditional Analysis of 'could have done otherwise' do not undermine the Bundle view.  I also argue that the objection that was widely accepted as fatal to the Simple Conditional Analysis was based on a mistake about counterfactuals.

CHAPTER SEVEN  Laws, Counterfactuals, and Fixed Past Compatibilism

The free will/determinism problem is one of the hardy perennials of philosophy and anyone who claims to have provided a solution has an obligation to explain why the problem has resisted attempted solution or dissolution for so long.  The common sense compatibilist faces an additional challenge: If compatibilism is true, why is it so hard to believe?  Why is the most common first response to determinism the incredulous stare and the second response some version of incompatibilism?   I  argue that if we evaluate an important class of counterfactuals in the way that David Lewis says we do, we can explain our incompatibilist impulse.  There is also a fringe benefit.   If Lewis is right about counterfactuals, and  the Bundle view is the correct account of our abilities, the common sense compatibilist can also be a Fixed Past compatibilist.

Time Travel: Horwich vs. Sider

In these last few posts I have been defending my argument that, even if time travel is possible, a time traveler would not be able to commit “auto-infanticide”.  In my last post I warned that confusing counterfactual with indicative conditionals can muddle our thinking about time travel.  In this post I offer, as a case in point, Ted Sider’s criticisms[i] of Paul Horwich[ii] and me.

Sider says that I argue "in effect" in the following way:    If time travel were possible, then "counterfactuals of co-incidence" like the following would be true: "If many, many time travelers went back in time intending to kill their earlier selves, equipped with deadly weapons, hardened hearts, and excellent information about their targets, there would be a long string of co-incidences: slips on banana peels, sudden attacks of remorse, mistaken identities, and so on."   A time traveler can kill her earlier self only if these "counterfactuals of co-incidence"  are not true.  Therefore, no time traveler can kill her earlier self.

But my argument mentions neither actual nor counterfactual co-incidences, nor does it say anything about the failure of "many, many time travelers" to murder their younger selves. Why would Sider think that this is  "in effect" my argument?

The answer lies in a thought experiment due to Paul Horwich.  Sider thinks that the thought experiment is the source of intuitions about the impossibility of time travel, and Sider thinks that anyone who thinks that time travelers cannot kill babies is also committed, whether or not they realize it, to an argument against the possibility of time travel.

Horwich's thought experiment goes something like this:[iii]

Suppose that time travel has been invented and that a confused consortium of philosophers establishes the Institute for Changing the Past and embarks on a grand-scale experiment for the purpose of proving that the past can be changed (and in significant, noticeable ways).  Because babies are easy to kill, and because the effects of killing are permanent (that is, the laws of physics don't permit resurrection from the dead), the Institute decides to focus its efforts on babies who are known to have survived infancy.[iv]  Some of the babies they target are babies who grew up to be famous or infamous historical figures -- Napoleon, Stalin, Hitler, Picasso, JFK. Others are ordinary folk, known only to their friends and family. And still others are the baby selves of the time travelers sent out to kill them.  The mission of each time traveler is to kill the particular baby who is her assigned victim, thereby providing experimental proof for the claim that the past has been changed, and, therefore, can be changed.

We know the outcome of the experiment in advance; the attempts will all fail.  The reason is not mysterious. They will fail because they did fail.  And so we can say, of each time traveler, and of each of her assigned targets: if this time traveler tries to kill this baby, she will fail.  This is an indicative conditional, and we evaluate it the way we evaluate the conditional about Oswald and Kennedy.  It doesn't matter how many time travelers there are, or how many assigned targets. The indicative conditional comes out true, every time, and for the same reasons.  And since we also know that every attempt, by every person whatsoever, to kill each of these babies failed, we also know that this indicative generalization is true: For every time traveler, and every baby on the target list, if the time traveler tried (tries) to kill the baby, the time traveler failed (will fail).

More generally, we know that the experiment of the Institute for Changing the Past is based on a misunderstanding about the nature of time travel.  Since there is only one actual past, it will occur in exactly the way that it did occur.  The targeted babies all lived to be adults, so all attempts, whether by time travelers or anyone else, to kill them will fail.   But it doesn't follow that the babies were somehow protected or that the time travelers were somehow disabled; it doesn't follow that the time travelers could not have killed them.  It is true, of many pairs of babies and time travelers, that this time traveler could have killed that baby; it just so happened that he didn't. It's not true that if he had tried again, he would have failed again. The failure to kill was not unavoidable; it was just bad luck.

For the reasons I have already given, it is different for those time traveler-baby pairs that consist of a person and her younger self. In those cases, the failure to kill was no accident. In those cases, the counterfactual, as well as the indicative, is true. If the time traveler had tried (again), he would have failed (again).   And because this is true for every time traveler-baby pair where the two individuals consist of a time traveler and her younger self, the following counterfactual generalization is also true: For every time traveler, and every baby who is that time traveler's younger self, if the time traveler had tried to kill the baby, the time traveler would have failed.[v]  

Horwich doesn't use his thought experiment to argue that time travel is impossible or that time travelers cannot kill the babies who are their assigned targets.  However, he does think that it provides the makings for an argument for the conclusion that time travel to the recent past will not occur.  His argument is based on the claim that if a large number of time travelers try to change the past, there will occur a pattern of events that is a certain kind of co-incidence and on the claim that we have good empirical evidence that this kind of co-incidence never happens.

Of course, we all know that co-incidences sometimes happen. A coin might come up heads 100 times in a row, and still be a fair coin. Someone might repeatedly fail to walk on a particular tile in the middle of her kitchen floor even though nothing prevents her from doing so. But ordinarily, over the long run, the law of averages kicks in, and  a fair coin comes up heads 50% of the time.  And, ordinarily, if someone walks about long enough in her kitchen she will, if she is a normal person in a normal kitchen, eventually step on the title that she missed, for no particular reason, the first one hundred times.  But in the time travel case, things appear to be different. The Institute for Changing the Past has a large budget and a great deal of patience; they repeat the experiment hundreds, thousands, tens of thousands of times. And every single time something happens to prevent the bullet from killing the baby. I have explained that it is no mystery that the Institute's experiment is a failure. But many people, including Horwich, remain bothered by the fact that such a large number of able-bodied time travelers repeatedly fail to kill unprotected babies.  Why do the time travelers keep failing?

Of course, each individual failure has a perfectly good causal explanation. There is no a priori reason to suppose that the explanations are anything out of the ordinary, so we may suppose, as defenders of time travel typically do suppose, that each time traveler's attempt is thwarted by some mundane event: the baby moved, the time traveler slipped on a banana peel, the bullet jammed, a bird flew in the path of the bullet.  And so on.  But why does a thwarting event always happen?  Why are attempts by time travelers to kill babies always correlated with thwarting events?  Here the answer seems to be:  no reason, it was just an accident, just a co-incidence.  But, says Horwich, there are no long-run accidents or cosmic co-incidences and this is due to a contingent but deep fact about the initial conditions of the universe.[vi] Therefore, he concludes, we have good empirical reason to believe that time travel to the recent past will never happen, even though it is logically and perhaps also physically possible.

Sider criticizes Horwich's argument,  but his main interest is in using Horwich's thought experiment for the purpose of constructing and criticizing several bad arguments for the claim that time travelers are unfree or that time travel is impossible.[vii] The arguments that Sider criticizes are, indeed, bad arguments. But they are very different from my argument. They are also different from Horwich's argument.  What's going on?

Horwich formulates his argument in terms of indicative conditionals. That’s all he needs, since his aim is to argue that we have good empirical reason to believe that time travel to the recent past (while logically and perhaps physically possible)  will not happen.  "Counterfactuals of co-incidence" play no role in Horwich's argument.

Sider's three bad arguments, by contrast, are all formulated in terms of counterfactuals. The key premise, of each argument, is that time travel entails "counterfactuals of co-incidence":

"If many many time travelers went back in time, intending to kill their earlier selves, equipped with deadly weapons, hardened hearts and excellent information about their targets, there would be a long string of co-incidences: slips on banana peels, sudden attacks of remorse, mistaken identities, and so on."

(In this passage, Sider restricts his attention to the case of time travelers trying to kill their own younger selves, but recall that Sider thinks that auto-infanticide is just a special case of the more general problem of the time traveler's ability to do other things she didn't actually do.)

In the bad argument that Sider attributes to me, there is an additional premise that says that a time traveler is able to kill her earlier self (Baby Hitler, etc.) only if these "counterfactuals of co-incidence" are not true.

Two points.

First, insofar as Sider uses these "counterfactuals of co-incidence" as a premise in an argument for the conclusion that time travelers are unable to kill their baby selves (Baby Hitler, the baby next door, etc.), Sider's counterfactuals are not the relevant ones.  Consider someone in a maximum security prison, and ask whether that person can kill a baby living on the other side of town. We don't answer this question by considering what would have happened if the person had escaped from prison and  traveled across town, equipped with deadly weapons, etc., intending to kill that baby!  We answer by asking what would have happened if he had tried to get across town to kill that baby. And the answer is 'no', because if he had tried, he would have failed at the first step; the prison walls would have stopped him.

Second, and more important. Why does Sider think it legitimate to replace Horwich's "indicatives of co-incidence" with "counterfactuals of co-incidence"?  We are not ordinarily  entitled to infer, from the truth of an indicative, to the truth of the corresponding counterfactual, and Sider gives us no reason to think we are  entitled to infer from 'if many many time traveler go back in time..., there will be a long string of co-incidences' to 'if many many time travelers went back in time...there would be a long string of co-incidences."   On the contrary, we have reason to suppose that "counterfactuals of co-incidence" are false, at least for the general case of time travelers trying to change the past (eg. by killing babies before the day of their death).  For if it really is just a co-incidence that all actual attempts by time travelers to kill their targeted babies have been thwarted by banana peels, etc., we have no grounds for supposing that counterfactual attempts would also fail due to thwarts. Only lawlike generalizations sustain counterfactuals; accidental generalizations do not.

This discussion of Horwich's thought experiment and argument, and of Sider's (unconscious?) permutation of Horwich's argument highlights the importance of distinguishing between indicative and counterfactual conditionals, as well as the importance of distinguishing between claims about ways in which a time travel world would be strange and different from the way we believe our world to be (which is what Horwich and I are concerned with) and arguments for the impossibility of time travel.

---

[i]   http://tedsider.org/papers/time_travel_and_coincidence.pdf

[ii]  Horwich, "On Some Alleged Paradoxes of Time Travel", Journal of Philosophy 72 (1975): 432-444.

[iii]  I am adapting Horwich's thought experiment somewhat for my own purposes, but I don't think either Horwich or Sider would object. Horwich wouldn't object because he describes his experiment in terms of "bilking attempts" and he defines bilking attempts as attempts to bring about some past event that did not occur, such as killing one's infant self or doing something one remembers was not done. (p.120). Sider would not object because he views attempts to kill one's infant self as merely an  "especially vivid example" of attempts to "do something that did not in fact occur". (p.1)

[iv]   So far as changing the past is concerned, it doesn't matter whether death is permanent or not.  Even if  the world is such that people are constantly rising up from the dead, the past would be changed if it were true that a person is both killed on a particular day and is not killed on that day.  I make this point to draw attention to the fact that while we usually think of killing as permanent, this is due to a contingent feature of the world, and not true by definition.  (Contrast Sider, p. 1.)

[v]  The points made in the last three paragraph are mine, but I do not think that Horwich would disagree with what I say in the first two of these paragraphs (at least).

[vi]  Horwich, Asymmetries in Time.  http://www.amazon.com/Asymmetries-Time-Problems-Philosophy-Bradford/dp/0262580888/ref=sr_1_8?s=books&ie=UTF8&qid=1318042966&sr=1-8

[vii]  The first argument runs thus:   time travel entails 'counterfactuals of co-incidence'; these counterfactuals are never true; so time travel is impossible. The second is the argument that he attributes to me: time travel entails "counterfactuals of co-incidence"; these counterfactuals entail the inability of time travelers to kill their younger selves (or Baby Hitler, or any other baby before the date of that baby's death). The third is another argument for the conclusion that time travelers are unable to kill their younger selves: time travel entails either "counterfactuals of coincidence" or  "strange shackles"; counterfactuals of co-incidence are never true; therefore time travel entails 'strange shackles'; therefore time travelers are unable to kill their baby selves (or Baby Hitler, etc.).

 

Counterfactuals, Indicatives and What Time Travelers Can’t Do

My argument is that a time traveler cannot kill her baby self, even if she travels back in time, heavily armed, and finds her baby self undefended, right in front of her,  even if anyone else similarly armed in the same position could kill the baby.

My argument is simply this.

First Premise: If Suzy would fail to kill that baby, no matter how many times or ways she tried to kill it, she cannot kill the baby.

Second Premise: Suzy would fail to kill that baby no matter how many times or ways she tried to kill it.

Therefore:

Suzy cannot kill that baby.

I spent my last post defending the first premise and the connection between abilities and counterfactuals it assumes. In this post I'm going to focus on the second premise.

Both premises of my argument are claims about counterfactuals. Counterfactual conditionals are different from indicative conditionals. If you don't notice this, you will misunderstand my argument.

Indicatives and counterfactuals have different truth conditions. The classic example of this in the literature is this pair of conditionals about Lee Harvey Oswald.

(1) If Oswald did not kill Kennedy, someone else did.

(2) If Oswald had not killed Kennedy, someone else would have.

If we assume that the Warren commision was correct, and Oswald was the only gunman present that day, then (2) -- the counterfactual conditional -- is false. But (1) -- the indicative conditional -- is true.

There is no general agreement, at the present time, about the correct semantics for indicatives (or even whether they have truth conditions), but it is generally agreed that they are sensitive to our subjective probabilities of belief in a way that counterfactuals are not. The so-called 'Ramsay test' for indicatives says that you should add the antecedent to your stock of beliefs, adjust your other beliefs in the most natural, conservative way, and then ask whether you now believe that the consequent is true. Since we are sure that Kennedy was killed that day in Dallas, we preserve this belief when we revise our beliefs by adding "Oswald didn't kill Kennedy" to our beliefs, and we conclude that someone else must have killed him.

Counterfactuals work differently. We evaluate counterfactuals by considering, not what we should believe, upon acquiring new beliefs about the actual world, but, rather, by considering whether the consequent is true at some relevant set of possible worlds where the antecedent is true. Counterfactuals are notoriously vague and context-dependent, but there is a standard or default way of resolving the vagueness of counterfactuals, and it is this standard resolution that we invoke when we say that (2) is false. There are, of course, possible worlds where Oswald was working with a team of back-up assassins, and at these worlds (2) is true; if Oswald had not killed Kennedy, one of the back-up assassins would have done the job. But these worlds are less like the actual world than worlds where Oswald is a sole operator (and where things are otherwise pretty much the way they are at the actual world). And these worlds -- the worlds most similar to ours - are the ones we have in mind when we say that (2) is false.  

Ability, ‘Can’, and Counterfactuals

I think that time travel is logically possible, but I think that even if it were physically possible no time traveler would be able to go back in time and kill her baby self. My argument has two premises:

Premise1: A person can do something (is able to do that thing) only if it isn't always true that: if he tried to do it, he would fail.

Premise 2: It is always true of Suzy, the time traveller, that if she tried to kill the baby who is her younger self, she would fail.

In this post I'm going to defend the first premise. That premise isn't specific to time travelers. It asserts a quite general link between our beliefs about what a person can do and the truth of certain counterfactuals. That is why (1) is worth thinking about quite apart from worries about time travel: it captures an essential feature of what we mean when we say that people are able to do things even if they don't do them. It  partly defines how we understand 'can' when we make choices: that is, when we choose to do one thing from among the other things we can do.

Fatalists and Hard Determinists Can Defend Time Travel

Before I defend my argument that the Time Traveller cannot kill her baby self I want to explain why it wouldn't matter -- so far as the possibility of time travel is concerned -- if I turned out to be guilty, as charged, of fatalism.

The Logical Fatalist is someone who thinks that there are truths about our future actions, and that these truths entails that we must do whatever we are going to do, that we can never do otherwise. Since you did not kill your baby self, you will not kill her, and thus, according to the fatalist, you cannot kill her. But time travel has nothing to do with it, says the fatalist. We are always in this position – we just don't notice it. The clearheaded fatalist will dismiss the Freedom Contradiction objection to time travel on the grounds that its 'can' premise is false.

The Hard Determinist is someone who thinks that determinism is true and that it follows, from determinism alone, that we are never able to do other than what we actually do. The hard determinist should also be able to defend the logical possibility of time travel. But surely the hard determinist's defense of time travel should not require him to defend the claim that the time traveler has abilities that he thinks we lack.

(After all, time travel worlds are worlds where, in addition to the usual earlier causes, some actions have causes that occur later in time. If you think that deterministic event-causation undermines freedom, you will have more, not fewer, reasons to think that this is so at time travel worlds.)

To summarize: the Freedom Contradiction objection to time travel succeeds only if it is true, without equivocation, that a time traveler both can and can't do something. Lewis's response to the Freedom Contradiction objection is to deny that the 'can' and 'can't' claims are unequivocally true. But the Freedom Contradiction objection can also be answered by denying the 'can' claim. If the time traveler cannot kill her baby self (or grandfather, or baby Hitler, or another baby, or a fly) there is no contradiction. The person who claims that time travelers cannot do things that most of us think he (and we) can do may be mistaken, but this is a separate issue. We should not confuse the defense of the logical or metaphysical possibility of time travel with a defense of the claim that the time traveler can do all the things that commonsense says we can do. Compare: We don't need to defend the claim that determinism is compatible with the ability to do otherwise in order to defend the claim that it is logically or metaphysically possible that determinism is true.

I should quickly add that I am neither a fatalist nor a hard determinist. Like most of the philosophers who defend time travel, I am a compatibilist. I don't say that the time travel is unable to do anything she fails to do. I say that the time traveler is able to kill a fly, to kill other babies. And even – kill baby Hitler. However I still think that the time traveler is not able to kill her baby self.

Two Objections to the Possibility of Time Travel

The Changing the Past Objection and the Freedom Contradiction Objection

My critics and I agree about many things. We agree that time travel is logically and metaphysically possible and we regard it as an empirically open question whether time travel is possible, given the actual laws and space-time of our universe. We agree that David Lewis and other defenders of time travel have given satisfactory answers to the standard objections to the possibility of time travel. Most of us agree about the metaphysics of time -- the 4D view -- and some of us agree that the best way to think about identity through time is to think of ourselves as four-dimensional objects, stretching across time in the way that a highway stretches across space. But even if we disagree about some of the details, we all agree that the standard objections to the logical and metaphysical possibility of time travel can be answered. We part company only on the question of what the time traveler is able to do. I say that the time traveler cannot kill the baby who is her younger self; my critics say that she can. But this is where things get complicated, since some of my critics think that my inability claim is not compatible with my claim about the possibility of time travel. So before I explain and defend my inability argument, I need to clarify my position concerning the possibility of time travel.

There are two different objections to time travel that are not always distinguished (or not distinguished carefully enough). I call these objections the 'Changing the Past' objection and the 'Freedom Contradiction' objection. If you don't distinguish these objections, you might be led to think, as Ted Sider does, that "there is nothing special about auto-infanticide"; it is simply "an especially vivid example" of the problems that arise:

"whenever a time traveler resolves to go back in time and do something that did not in fact occur. A time traveler who remembers owning a 1974 Plymouth Gold Duster, could, it would seem, go back into the past and prevent herself from ever owning such a fine automobile; a time traveler could, it would seem, go back and prevent Lincoln from giving the Gettysburg address, and so on."

Sider is mistaken, and his mistake is due at least partly to his failure to distinguish these two different objections.

The more simple-minded objection is the Changing the Past objection. It says that time travel is impossible because it entails changing the one and only actual past, which is impossible. Lincoln already gave the Gettysburg address, so you can't travel back in time and stop him from doing it. (Contradictions would be true if Lincoln both gave and did not give the Gettysburg address, and contradictions can't be true.) Your next door neighbor lived to be an adult, so you can't travel back and kill him when he was still a baby. (Contradictions would be true if your next door neighbor was both killed as a baby and not killed as a baby.) And you lived to be an adult, so you can't travel back and kill yourself when you were still a baby. (Same reason; note that it doesn't matter who does the killing.)

Auto-infanticide can, indeed, be understood as an especially vivid example of the "Changing the Past" objection. But it is important to see that this objection has nothing to do with freedom or ability (or any alleged contradictions concerning the time traveler's freedom or ability). The 'Changing the Past" objection arises even if we assign a Guardian of the Past to every time traveler, to ensure that he will not (because he cannot) do anything that contradicts any of the known historical facts. The objection arises the moment the shackled and guarded time traveler arrives in the past. John Hospers puts the objection in a particularly clear way:

"Many centuries BC, the pyramids were built, and when all this happened you were not there – you weren't even born. It all happened long before you were born, and it all happened without your assistance or even your observation. This is an unchangeable fact: you can't change the past. That is the crucial point: the past is what has happened, and you can't make what has happened not have happened…for this is a logical impossibility. When you say that it is logically possible for you (literally) to go back to 3000 BC and help build the pyramids, you are faced with the question: did you help them build the pyramids or did you not? The first time it happened, you did not; you weren't there, you weren't even born, it was all over before you came on the scene. All you could say, then, would be that the second time it happened, you were there – and there was at least a difference between the first time and the second time: the first time you weren't there, and the second time you were there."

Defenders of time travel call this 'the Second Time Around' mistake; the cure for the mistake is to think of time the 4D way and to think of the time traveler as a four-dimensional object. The time traveler who is about to embark on a journey to the past has already been in the past; the historical record already includes his footprints in the sand, his labor on the pyramids, and so on. He doesn't remember any of this because it lies in what Lewis calls his "personal future". But it has already happened, so the past is safe from being changed, and logic safe from contradiction. If the time traveler is about to travel to the past to be in the audience to hear the Gettysburg address, then it is already true that he was there, and already true that he did exactly those things that, from his present temporal perspective, he is about to do.

The second objection, which is more subtle, is sometimes called "the Grandfather problem" or, more recently, "the auto-infanticide problem" and I think that there is a reason why the objection is always introduced by telling stories about failed attempts to kill grandfathers or baby selves. But insofar as the problem counts as as objection to the logical possibility of time travel, it is an objection that can be raised concerning any case where it seems that we are committed to contradictory claims about the time traveler's freedom or ability.

The alleged contradiction lies, not in anything a time traveler actually does, but in the things she doesn't do, but, in some ordinary sense of 'can', can do. The time traveler at the Gettysburg address won't cause a disruption that prevents Lincoln from giving the address (because he didn't). But, it seems, he can. After all, he is in the audience; and, we can easily amend our story so he is carrying a gun and nothing, it seems, stops him from firing it. And that appears to be all it would take to prevent the address from being given -- at least on that day. Actual murder or even physical injury is surely not required. The threat of death or serious harm to Lincoln would have been enough to prevent Lincoln from giving the address (that day). So it seems that our time traveler can prevent the Gettysburg address. On the other hand... Well, on the other hand, what?

The Freedom Contradiction objection is based on the claim that a time traveler both can do something that he didn't actually do and also that he can't do that very thing, and this, it is alleged, is a contradiction. Since there is no possible world where contradictions are true, it follows that time travel is impossible.

But there doesn't seem to be a contradiction in the case of the time traveler who attends the Gettysburg address. Granted, he won't do anything that prevents the address from being given. (Because he didn't.) But he seems to be in as good a position as anyone in the audience that day to cause a disruption that would have prevented the address. Of course, if he (or anyone else) had caused such a disruption, the subsequent course of events would have been different, and the historical record (from our perspective) would also have been different. But this is unproblematic; if any historical event had happened differently, or failed to happen, this would have had ramifications for the rest of history.

So the Freedom Contradiction objection does not arise in this case. (Or, at least, it does not arise if we understand the correct response to the 'Changing the Past' objection.) The time traveler won't cause a disruption, preventing the address, but there is no reason to say that he can't.

If we consider other cases, it seems even more clear that the Freedom Contradiction objection doesn't arise. Suppose the time traveler travels back to the year 500 and finds herself on a deserted island, near a beach. She doesn't go for a walk on the beach, but there is no reason to think she can't. Or suppose that the time traveler travels back to her own past and walks right past the house where she lived as a baby. She pauses for a moment, contemplating whether to ring the doorbell, but in the end decides not to. Again, there is no particular reason to think that she could not have rung the doorbell.

The Freedom Contradiction objection, unlike the Changing the Past objection, does not automatically arise with respect to every case of time travel to the past, nor does it arise with respect to every claim about the time traveler's freedom. The objection, if there is one, arises for a restricted set of cases, of which auto-infanticide is the most compelling example. Whether it is correct or not, almost everyone's intuitive response is that the time traveler cannot kill the baby who is her younger self. The time traveler's very existence depends -- causally, counterfactually, nomologically -- on the survival of the baby. In trying to kill the baby, she is trying to prevent her own present existence. Of course, that's bound to fail. Or so it seems.

On the other hand, if we saw only an adult and a baby, without knowing that one is a time traveler and the other is the time traveler's baby self, we would say: "Of course, that adult can kill that baby." She's got what we would ordinarily call the ability (the skills and physical capacity), and she has what we would ordinarily call the means and opportunity. (She's got a gun, and is right beside the unprotected baby.) She's got what it takes and she's in the right place at the right time. Even if her first attempt fails, that's just bad luck. She is able to kill that baby.

So there is definitely a puzzle here, a puzzle that I will be addressing in these posts. But does this case count as an objection to the possibility of time travel?

It counts as an objection only if we are committed, as the Freedom Contradiction objection alleges, to the claim that it is both true that the time traveller can kill the baby who is her younger self and also false that she can kill that baby.

I deny that we are committed to any such contradiction. My argument will show that it is false that the time traveler can kill the baby who is her younger self, given what we ordinarily mean by 'can'. If we are tempted to think otherwise, it is because we are relying on an assumption about ability to which we are not entitled at time travel worlds.

I also deny that there is any other case in which we are committed to inconsistent claims about what the time traveler can do. Either it will be true, given what we ordinarily mean by 'can', that she can do something, or it will be false. In no case will it be both true and false that the time traveler can do something. The Freedom Contradiction objection to the possibility of time travel fails .

Before I move on, I need to say something about David Lewis's well-known reply to the Freedom Contradiction objection.

According to Lewis, "can" always means " compossible with some set of facts F", with intentions of speaker and context fixing the relevant facts F. In order to avoid equivocation, we must be careful to specify the relevant facts. Just as we don't contradict ourselves, but only equivocate, when we say that a baby elephant is both big (for an animal) and small (for an elephant), we don't contradict ourselves, but only equivocate, when we say that the time traveler both can and can't kill his baby self. Given the way we ordinarily use 'can'; the time traveler can kill his baby self; his doing so is compossible with facts about his shooting skills, the proximity of the unprotected baby, and other intrinsic facts about himself and his surroundings at the time of the contemplated killing. Given the way the fatalist uses 'can', the time traveler cannot kill his baby self; his doing so is not compossible with the fact that the baby will grow up to be him. So there is no contradiction, and if you think there is, you have been taken in by fatalist trickery.

Almost every philosopher who defends the possibility of time travel assumes that David Lewis gave the correct response to the Freedom Contradiction objection; indeed, Lewis's reply is so widely accepted it has become known as "the Standard Reply". Some philosophers even think that you must accept Lewis's reply in order to defend the possibility of time travel. These defenders of time travel think it important to claim that time travel doesn't cramp our style in any way, and to argue that anyone who thinks that it does is guilty of some fatalist mistake.

(Here there is a striking contrast with the literature on the free will/determinism problem where it is routinely claimed that determinism or a Frankfurt-style "counterfactual intervener" would deprive us of all "alternative possibilities" and hardly anyone worries about fatalist trickery. But I digress.)

I think that the defenders of the Standard Reply are mistaken. You don't need Lewis's account of 'can' to respond to the Freedom Contradiction objection; there are other ways of responding, as I just suggested. And while it's true that the Freedom Contradiction objection is often fueled by fatalist confusions, it's not true that anyone who thinks that time travel makes a difference to our freedom is guilty of the fatalist's collapse of "will not" and "cannot". My argument, at least, is based on no such mistake. My claim, once again, is that the time traveler cannot kill the baby who is her younger self, given what we ordinarily mean by 'can'.

What TimeTravelers Cannot Do

This is first of a series of posts on TimeTravel.

I'm interested in the philosophically interesting kind of time travel, by which I mean time travel to the one and only actual past, and, in particular, to your past, to the time when your parents were children, or to the time when you were a baby. I won't be talking about time travel to a parallel universe or to a different dimension of time. I will also be limiting my attention to cases of time travel at possible worlds that are as much like ours as is consistent with time travel; so, unless there is reason to suppose otherwise, I will be assuming that a time travel world is governed by laws much like our own laws.

I believe that this kind of time travel is logically and metaphysically possible.

This is now the majority view, at least among those who think and write about time travel . So this part of my view is not especially interesting.

However, I depart from the other defenders of time travel in insisting that time travel, while possible, is very odd. David Lewis, whose 1976 paper, "The Paradoxes of Time Travel", remains the classic defense of time travel, said that time travel is possible but also cautioned us that "a world where time travel took place would be a most strange world, different in fundamental ways from the world we think is ours". Lewis's paper succeeded in convincing many philosophers that time travel is possible. Indeed, he succeeded so well that some of the contemporary defenders of time travel argue that time travel isn't merely possible, it isn't that strange either.

I disagree. Time travel is possible, but I insist that it is also strange. Time travel worlds are backwards causation worlds – worlds where some causes happen after their effects – and this makes a huge difference to our common-sense view of the world and ourselves.

These posts are about one of the ways in which time travel is strange. I will be arguing that if our world turns out to be a time travel world, then we are not entitled to some of our common-sense assumptions about our abilities. If our world is a time travel world, then we have some abilities that common-sense says we do not have. And if our world is a time travel world, then we lack some abilities that common-sense says we have. But before I get to this, I want to point out another way in which time travel is very strange.

Frankfurt's Bold Gambit and the Long Debate that Followed

Frankfurt noted that all parties to the traditional debate about the compatibility of free will and moral responsibility with determinism had subscribed to a common assumption. They had assumed the truth of something Frankfurt called “the Principle of Alternate Possibilities”, which he expressed as follows:

(PAP) A person is morally responsible for what he has done only if he could have done otherwise.

In the traditional debate incompatibilists had argued that if determinism is true, then no one could ever have done otherwise, while compatibilists argued that there is a morally relevant sense in which even a deterministic agent could sometimes have done otherwise. Frankfurt proposed to show that PAP is false, thereby undercutting the traditional debate.

Whatever we think of Frankfurt's argument, we must agree that Frankfurt succeeded in changing the way philosophers think about these issues. A principle which was once almost universally accepted as a commonsense truism or even an a priori truth is now widely regarded as false, or, at the very least, highly controversial. Among compatibilists, I think it fair to say, the received view is that PAP is false and that therefore the traditional free will/determinism debate -- the debate about whether determinism has the consequence that we are never able to do otherwise -- is irrelevant to questions of moral responsibility. More surprisingly, some incompatibilists have also been convinced that someone might be responsible even though he is unable to do otherwise. The upshot is that there is now a literature devoted to the challenging task of providing a new rationale for thinking that determinism deprives us of freedom and responsibility. At the same time, there are philosophers who strenuously deny that Frankfurt has succeeded in showing that PAP is false.

It’s difficult to explain, to someone not working in this area, just how peculiar the situation is. On the one hand, Frankfurt stories, as they have come to be called, have had an impact in free will circles that is comparable to the impact of Gettier stories in epistemology. On the other hand, after forty years of debate and discussion, it is still controversial whether Frankfurt or any of his followers have succeeded in providing a genuine counterexample to PAP.

If Frankfurt’s aim was to convince incompatibilists that, even if determinism renders us unable to do otherwise, it does not undermine responsibility, he has failed. If his aim was to make it easier to defend compatibilism, he has failed. And if his aim was to bypass questions about how, exactly, we should understand locutions like 'he could have done otherwise', he has also failed, for the debate that has arisen in the wake of his original thought experiment is now mired deep in the very metaphysical questions he sought to avoid.

But in a way Frankfurt has been successful. The main debate in the current free will/determinism literature is no longer about whether a person at a deterministic world is able to do otherwise; it is about whether the person in a Frankfurt story is unable to do otherwise.

It is my view that this literature is a philosophical dead end. Although I am a compatibilist, I think that Frankfurt’s strategy for defending compatibilism is a bad one. If we begin with the commonsense view that someone is morally responsible only if she could have done otherwise, then Frankfurt stories will not and should not change our minds. If we are persuaded by Frankfurt, it is because we have been taken in by a bad argument.

Frankfurt is not usually thought of as providing an argument. The literature talks about Frankfurt stories as if they were, like Gettier stories, ingenious counterexamples to a once widely accepted philosophical thesis. So let’s begin by seeing how such stories are supposed to change our minds about what’s necessary for moral responsibility.

Frankfurt’s argument against PAP is based on a simple thought experiment. It begins by inviting you to tell a story about an agent, Jones, who chooses to perform, and succeeds in performing, some action X. Tell the story so that it is vividly clear that Jones is morally responsible for doing X. If you are an incompatibilist, you may specify that Jones is an indeterministic agent who is able to choose and do otherwise, given the actual past and the laws. If you are a compatibilist, you may fill in the details so that Jones does X in a way that satisfies your favorite account of the counterfactual or dispositional facts that make it true that Jones could have done otherwise in the sense you think relevant to responsibility. Now, add to your story the following facts: There is standing in the wings another agent, Black. Black is interested in what Jones does. In particular, he wants Jones to do X and, moreover, Black has it in his power to prevent Jones from doing anything other than X.

Just how Black might force Jones to do X is, Frankfurt averred, not vital to the story. Perhaps Black is standing in the wings ready to offer Jones a coercive threat that would "stampede" Jones into doing X. Or maybe Black has a drug or a hypnotic procedure that would give Jones an irresistible desire to do X. Or maybe Black has a device in place which would directly affect Jones’ nervous system in such a way that Jones’ body would be forced to move, puppet-like, through an execution of X. Fill in the details as you like, so long as it is clear that Black can and would prevent Jones from doing anything but X.

The addition of Black to the story means that Jones could not have done other than X. But, Frankfurt argued, Jones is still responsible for doing X. After all, though Black could have intervened, he didn't. He didn't have to. Jones chose to do X and did X without any interference from Black. So the addition of Black to our story doesn't remove or in any way diminish Jones’s responsibility for doing X.

Such is the recipe for telling a Frankfurt story. And such stories can be told. Stories, that is, in which everyone should agree that an agent is responsible for doing something even though everyone should also agree that the agent could not have avoided doing that thing. And such stories do indeed tell us something interesting about responsibility. Such stories show us that it is false that:

PAP* A person is morally responsible for doing X only if that person could have done other than X.

Thus, whatever your views about freedom, if you thought that John Wilkes Booth freely chose to kill Lincoln and hence is responsible, it would be absurd to change your mind if you discovered that there happened to be a Black-like figure waiting passively in the wings, prepared to force Booth’s hand had Booth changed his mind. Given the choices he made and the actions he took, Booth is responsible for killing Lincoln even if he could not have avoided killing Lincoln.

This much everyone should agree to. We’ve always known that there is a gap between the choices an agent makes and the outcomes of those choices. Two drivers choose to drink and drive, but only one has a fatal accident; we hold the second driver responsible not just for his choice but also for the death regardless of whether he was able, at the time of the accident, to avoid causing death. And we've always held agents responsible for the outcomes of their actions even if these outcomes would have come about anyway, due to a back-up cause. Thus we all agree that Booth was responsible for Lincoln's death even if there was a back-up assassin ready to kill Lincoln if Booth's attempt failed. Black is like the second assassin, except that he would operate by forcing Booth's hand should Booth fail to attempt the assassination. Black's presence on the scene guarantees that Lincoln will end up dead, by Booth's hand, but he does not deprive Booth of responsibility for either the death or the murder. After all, in the actual world Booth acts as he does, not because of anything Black does, but because Booth chooses to act that way. And, we could add here, no matter what happens to come of that choice, Booth's choice is free and he is responsible for it precisely because there is at least one moment at which Booth could have chosen otherwise.

Reflection on cases of real life causal pre-emption shows how far PAP* is from PAP. In real life, we hold persons responsible for outcomes they could not have prevented, provided that these outcomes are the foreseeable consequences of actions they could have avoided. Frankfurt stories show that we are also prepared to hold someone responsible for an action he could not have avoided, provided that the action is the foreseeable consequence of a choice he could have avoided making. This is enough to refute PAP*. But PAP says that an agent is responsible only if he could have done otherwise. Otherwise than he actually does. To refute PAP one would have to tell a story in which an agent is responsible for what he did even though he could not have done anything other than he actually did. But Frankfurt stories of the sort just told do not fit that bill. They do nothing to subvert the view that moral responsibility requires the agent’s ability to do something otherwise --- even if that is only to make a different choice.

What is needed to refute PAP and sustain Frankfurt’s claim that alternatives are unnecessary for responsibility is a different kind of story. What’s needed is a story in which Jones does X and is responsible for doing X, but we must concede that Jones cannot do anything, even deliberate, decide, or choose, other than he actually does.

Frankfurt himself never tells such a story. When speaking of PAP he speaks only of responsibility for overt actions - the things we do by moving our bodies -- as opposed to responsibility for mental acts like choices or decisions, and he seems to think that demonstrating the falsity of PAP* suffices for demonstrating the falsity of PAP. But he also seems to assume that such a story can be told. That is, he seems to assume that the schema for the thought experiment sketched above can be filled out in a way that ensures that Jones can neither do nor decide (deliberate, try...) otherwise.

Whether or not that is so has turned out to be the central issue in the post-Frankfurt debate. Forty years later, no one has succeeded in telling a story that uncontroversially meets Frankfurt’s specifications. Not that there has been a shortage of attempts. Lots of philosophers have been convinced by Frankfurt, and they have tried to convince the rest of us. Their stories typically depict Black as a highly skilled neurosurgeon who has cunningly inserted devices in Jones’ brain that allow him to monitor and alter Jones’ brain states without Jones ever noticing. Black can intervene, if need be, causing brain states in Jones which are the physical realizations of the choices and decisions Black wants him to make. But as luck would have it, Jones deliberates, decides, and acts in just the ways that Black wants, so Black never has to intervene. Since Black never intervenes, Jones’ moral responsibility remains intact. But Black’s intentions and power guarantee that Jones can neither do nor even decide otherwise.

The philosophers who remain unpersuaded by these kinds of stories divide into two main camps. Some philosophers have argued that since the choices of an indeterministic free agent are not predictable in principle, Black cannot intervene until after Jones has chosen and this ensures that there is at least a moment during which an indeterministic Jones remains free to choose otherwise.

Other philosophers do not appeal to the unpredictability of Jones’ free choices but insist that even if Jones is predictable and controllable, Frankfurt stories, by their very nature, cannot rule out all of Jones’ alternative possibilities. They argue that there is necessarily a difference between the causal history leading up to Jones’ action in the actual scenario and the causal history leading up to Jones’ action in the counterfactual scenario in which Black intervenes. Because there is this difference, there is something that remains up to Jones, even if it is only whether he does or chooses X with or without Black’s intervention.

There are replies to these sorts of arguments. Against the claim that indeterminism entails unpredictability, defenders of Frankfurt have argued that even the choices of an indeterministic agent might be reliably correlated with – even though not caused by – some prior “blush” or other involuntary sign, and therefore predictable on that basis. Others have told stories in which Black has a godlike omniscience to predict what even an indeterministic agent will decide.

As for the second argument – that there is a difference between choosing X and choosing X because Black makes you, John Fischer has argued that this difference is not “robust” enough to “ground” attributions of responsibility. After all, if it is conceded that Jones’s choice is predictable because, say, Jones (deterministic or not) always blushes in a certain sort of way before he even begins to try to make his choice, then we can imagine a Black who can prevent Jones from even beginning to choose by watching for the blush. But in that case the only difference between what Jones actually does and what he would have done if Black had intervened is the blush or some other involuntary sign that Jones manifests before he even begins to try to decide what to do. Surely, Fischer argues, such a mere “flicker” of freedom – the freedom to “do” something that is not even an action – is not significant enough to be relevant to Jones’ responsibility.

And so it goes. Incompatibilists insist, for the most part, that they are unconvinced by Frankfurt’s claim to have refuted PAP. Compatibilists almost unanimously insist that PAP is false and that Frankfurt has shown that the traditional debate is irrelevant. New and ever more arcane Frankfurt stories continue to be told. Inevitably, the discussion turns to an argument about which side has the burden of proof, always a sure sad sign of a philosophical impasse.

I think we should have avoided this mess. Things went wrong from the start. No one should ever have been persuaded by Frankfurt’s argument.

I agree, as I have already said, that Frankfurt stories succeed in showing that we don't think about moral responsibility in quite the way we thought we did. They show that we reject PAP*; they show that we are prepared to hold someone morally responsible for doing something even if he could not have avoided doing that thing. More specifically, they show that we are prepared to hold responsible -- and even to blame -- someone whose actions do not depend, causally or counterfactually, on his decisions, choices, or efforts. If our intuitive response to the stories is justified, then we may be morally responsible for our actions even if it turns out that the movements of our bodies are never up to us in the way we think they are. This is a surprising result, not sufficiently appreciated by Frankfurt's opponents, and it at least partly explains why Frankfurt stories have dominated the free will literature for so long. However, the stories do not show what they need to show, in order to undermine the traditional debate; they do not show that the Moral Premise of the No Alternatives argument is false.  Nor do they show that PAP is false. In order to show that PAP is false, Frankfurt needs a story about someone who is morally responsible even though he has no choice whatsoever; that is, even though he is unable to decide otherwise, or deliberate otherwise, or even to begin or try to deliberate or decide otherwise. I will argue that no such story can be told.

Before I can do this, I need to draw a distinction between two very different ways in which Black might operate.

Choice, Alternatives, and Moral Responsibility

Why does it matter whether we have free will? Common sense and tradition say that it matters because free will is a necessary, though not sufficient, condition of having the kinds of choices that we care about.

We value free will because we value being in a position where we have a chance to make a difference -- a difference to our own lives, a difference to the lives of those we care about, and to the world more generally. Insofar as we are reflective creatures, we value our ability to choose and act on the basis of reasons and reasoning because we want our choices and actions to make a difference, for better rather than worse, to our own lives and the lives of others. Since 'better' need not mean 'morally better', our interest in free will is not limited to our interest in moral responsibility. But insofar as we are moral creatures, we care about free will because we care about being in a position to make choices that make a moral difference - choices between good and evil, between doing our duty and doing what's in our own best interest, and the more complicated choices we make in cases where our prima facie duties are in conflict. In making these kinds of choices, we also assume -- at least typically -- that we are morally responsible agents, accountable to others for our actions, and praiseworthy or blameworthy for our choices. And we assume that we would not be morally responsible agents if we did not have free will. That is, we assume that free will is a necessary, though not sufficient, condition of being morally responsible for our choices and actions.

There are differences, corresponding to differences in temperament and outlook in life, in how we think about the relationship between choice, and the kind of control that accompanies choice, and moral responsibility. Some people are more comfortable than others with the existence of what has come to be known as "moral luck", that is, with the idea that the extent to which we succeed in leading a morally admirable life is, to a significant degree, not in our control. On one extreme is the idea that there are moral dilemmas; that is, that it is possible to find yourself in circumstances in which, due to no present or earlier fault of yours, you are unable to avoid doing something wrong. (You have a choice, and you are able to do otherwise, but no matter what you choose, you will do something morally wrong.) At the other extreme is the Kantian idea that, regardless of the degree to which we are otherwise at the mercy of "the slings and arrows of outrageous fortune" we are not at the mercy of luck so far as our moral virtue is concerned. (We are always able to avoid being blameworthy, and it is in our control how blameworthy or praiseworthy we are, not just for the particular choices we make and the actions we perform, but also with respect to our lifetime moral record.)

But setting aside these differences, common sense and tradition sees the link between moral responsibility, free will, choice, and ability to do otherwise in something like the following way: We are morally responsible only if we have free will, and we have free will only if we are choice-makers who are at least sometimes in circumstances in which we really have a choice about what to do, and we really have a choice about what to do only if we are able to do otherwise. Being able to do otherwise isn't sufficient for responsibility - young children are sometimes able to do otherwise but are not (yet) morally responsible for anything - but it is necessary and this explains why we believe that only human beings and not, for instance, rocks, earthworms, or machines, are morally responsible.

Classic Compatibilism and Commonsense

Thanks to all who attended the Pacific APA session on “Classic Compatibilism” with myself, Bernard Berofsky, Randy Clarke, and Al Mele, and thanks especially to Joe Campbell for organizing and chairing.

As always at these things, there wasn’t enough time so I thought I’d use the blogosphere to round out the discussion.

Dispositions and Classic Compatibilism

I'll begin with a few remarks about a view that  Berofsky calls 'Dispositional Compatibilism", which he attributes to me and says is mistaken. 

I admit that I once wrote a paper with the deliberately provocative title "Free Will Demystifed: A Dispositional Account".   However, I didn't coin the term "Dispositional Compatibilism", and I wish here to explicitly disown it, for three reasons.   (In addition to the fact that 'Classic Compatibilism' has a much classier sound!)

First, it's given some people the false impression that I am committed to claims that are clearly stupid.  I say that we have abilities to act  by having certain dispositions, and that having the ability to choose and act otherwise entails having certain dispositions.  I don't say that any time you have a disposition, you have something with the ability to refrain from acting, nor do I say that any time something has a disposition, it is up to that thing whether it manifests its disposition.  I don't say that a lump of sugar has the ability to refrain from dissolving. Nor do I say that it's up to the sugar whether it dissolves when placed in water.  That would be stupid.

Second, it's given some people the false impression that I am committed both to the claim that we are agents with free will by having the relevant dispositions to act and choose  and also to the claim that something like Lewis's Reformed Conditional Analysis of disposition is correct.  I'm inclined to defend the second claim, but I don't need to.   No one doubts that dispositions like fragility and solubility (that is, dispositions with an intrinsic causal basis) exist. My claim is only that the dispositions that ground the facts about our agency and free will are dispositions of that kind -- whatever that turns out to be. 

And, finally, I don't like the name because it conveys the false impression that my defence of compatibilism is limited to the claim that the abilities relevant to our agency and free will are intrinsically based dispositions.  My earlier paper may have given this impression, though even in that paper I explicitly said that the ability to choose is not any single disposition, but, rather,  a bundle of dispositions (roughly, those dispositions that make it true that we have the ability to make choices on the basis of the evidence available to us, our reasons, and our reasoning).  However, in today's paper, I introduce a distinction, between narrow and wide abilities, that is neutral between compatibilist and incompatibilist accounts of ability, and which therefore does not pre-judge the question of whether our abilities to act are dispositions (or bundles of dispositions). To have the narrow ability to do something is to be in some intrinsic state that makes it true that you have what it takes to do that thing. To have the wide ability to do something is to have the narrow ability to do it and also for it to be true that nothing extrinsic renders you unable to do that thing. Narrow abilities are, by definition, those abilities that are shared by duplicates governed by the same laws; wide abilities are the abilities that are not shared by duplicates governed by the same laws.  Since we may be rendered unable to do something by prison guards or Frankfurt-style interveners, having the narrow ability to do something is not sufficient for being able to do that thing in the sense relevant to deliberation and choice.  When I say that I believe that determinism is compatible with the ability to choose as well as do otherwise, I mean that it's compatible with not only the narrow but also the wide ability to choose and do otherwise.  So, to bring it back to dispositions: I believe that we have narrow abilities to act and choose by having the appropriate dispositions or bundles of dispositions, and I believe that we have the wide ability to choose and do otherwise by being suitably lucky with respect to our surroundings.  To use the terminology of the dispositions literature, determinism does not entail that we are always masked or finked. If we've got what it takes and have the right kind of luck in our surroundings, then, I say, we are not only able (wide) to choose and  do what we actually choose and do; we are also able (wide) to choose and do otherwise.  What more could you want?

Objections to the Bundles of Dispositions Account

Bernie and Randy both cited cases they thought were counter-examples to the  'bundles of dispositions' account that I defended in my earlier paper.  Bernie said that the panic-stricken woman I described in that paper has the ability to scream (the causal basis of the disposition is still there), but can't scream because she can't try to scream. Randy said that he has the ability to choose to crow like a rooster despite his lack of any disposition to so choose.  Randy also said that he might have a disposition to choose compulsively to wash his hands, but his choice is neither free nor up to him.  

I don't think these are counter-examples.  I say that the panic-stricken woman retains the ability (and the disposition) to scream if she tries; if we don't hold her responsible it's because we think she's temporarily lost the ability to choose or try to scream (and, I claim, she's lost at least one of the dispositions in virtue of which she has this ability). I deny that there is any such thing as the ability to choose to crow like a rooster; there is only the ability to choose whether to crow like a rooster. Randy exercises this ability when he contemplates the matter and decides not to produce this interesting sound effect.  For the same reason, I deny that the correct description of a compulsive hand washer is that the person makes a compelled choice to wash his hands.  Either Randy chooses whether to wash his hands - in which case his choice is free and up to him - or he not only doesn't, but cannot, choose whether to wash his hands. In either case, there is no such thing as the unfree choice to wash one's hands; here I agree with Frankfurt. ("Concerning the Freedom and Limits of the Will").

Randy's Attempt to Save the Consequence Argument

Randy tried to save the Consequence argument by arguing that if determinism is true we can't stick with our commonsense beliefs about our abilities by endorsing my (A1), which says that my ordinary ability to raise my hand is merely the surprising but non-incredible ability to perform some act such that if I had done it,  the laws or the past would have been different.  He says that we are forced to endorse a version of my (A2), which says that my apparently ordinary ability to raise my hand is actually the incredible ability to do something such that if I had done it, my action would have caused the laws or the past to be different.  We are forced, he claims, to say that my apparently ordinary ability to raise my hand is, in fact, the incredible ability to bring it about that miracles occur. (This is, presumably, a way of bringing it about that the laws are different.)

I am puzzled by Randy's insistence that the Classic compatibilist must endorse Lewis's theory of counterfactuals.  I'm happy to grant him that Lewis's theory works pretty well; it might even be the closest approximation we have to a correct theory for a large and important class of counterfactuals.  But not everyone agrees, and at the end of the philosophical day it might turn out to be the case that we always evaluate counterfactuals by holding the laws fixed.  And if that's so, there is no question of common sense being committed, if determinism is true, to the claim that we have the ability to bring it about that miracles occur.  So my question for Randy is this: Does his attempt to save the Consequence argument require the truth of Lewis's theory of counterfactuals?  And if it doesn't, what is wrong with the  "equivocation" response to the argument?  In my paper, I gave Lewis credit for that response, but versions of the same reply were also made by John Fischer ("Incompatibilism", 1983, "Freedom and Miracles",1988, and The Metaphysics of Free Will, 1994); Gary Watson ("Free Action and Free Will",1987); and, most recently, by John Perry,  ( "Can't We All Just Be Compatibilists?", 2008).

But let's grant Randy the claim that Lewis's theory of counterfactuals, or something in the ballpark of Lewis's theory -- perhaps the theory defended by Jonathan Bennett in his recent book, A Philosophical Guide to Conditionals -- is correct.  I still think he's wrong to think that commonsense plus determinism commits us to incredible claims about our abilities.  Let me try again to explain why.

Pretend that determinism is true. I say that common sense doesn't,  for that reason, turn out to be mistaken.  I can raise my arm, right now.   Past tense: I could have raised my arm, a moment ago, even though I didn't.  I had the (wide) ability. I was able to do it.

Why do I think this?  All sorts of reasons, including my past and present experience of raising my arm.  I believe that I've got "what it takes" - I have the skills, competence, and physical capacity to raise my arm.  I also believe that there was nothing in my surroundings that would have prevented me from raising my arm; I believe that if I had chosen or tried to raise my arm, just then, I would have done so. 

Randy says that determinism plus Lewis's way of evaluating counterfactuals makes trouble for commonsense.  If I persist in saying that I'm able to raise my arm, I must say that I'm able to perform miraculous actions. 

I disagree.  I say that I'm able to raise my arm. That's no miracle.  And if I had, contrary to fact, raised my arm a moment ago, that would not have been a miracle either.  The event that Lewis calls 'the divergence miracle'  would have been over and done with by the time I raised my arm.

Randy says that  if I had raised my arm, my choice would have been the miracle. And since choices are actions, my claim that I'm able to raise my arm commits me to the claim that I'm able to perform miraculous acts (and thus able to bring it about that miracles occur).

Again, I say 'no'.  I say that I was able to raise my arm.  I agree that if I had raised my arm, my choice might have been the divergence miracle.  But it need not have happened this way. I can raise my arm without performing any prior mental act of choice -- on impulse, whim, because I just happen to feel like it. So it's false that if I had raised my arm,  this would have been because I first performed a miraculous act of choice.

But don't I agree, then, that I have a miraculous ability to choose?

No.  I believe that I was able to choose whether to raise my arm.  That's not a miraculous ability.  My reasons for believing that I have this ability - and had it a few minutes ago - are similar to the reasons I have for believing that I am now, and was then, able to raise my arm. I've had lots of past experience of making choices in general and choices concerning arm-raising more specifically.  I've got no reason to believe that I am now, or was then, in a state that renders me incapable of choosing whether to raise my arm; I'm not asleep, hypnotized, under the influence of mind-altering drugs, or subject to the manipulations of a nefarious neurosurgeon, and so on.  Of course, it might turn out that I'm mistaken about these facts. But if I'm mistaken, it's not because determinism is true.  So I say I remain entitled to my commonsense belief that I was able to choose whether to raise my arm.

But, says Randy, you are ignoring the fact that if you had made this choice that you say you were able to make, that would, or at least might, have been a miracle.  Do you claim, then, that you are able to perform miracles?

No.  A few minutes ago, I neither raised my arm nor made any choice concerning arm-raising.  Commonsense says that I was able to raise my arm and I was also able to choose to raise my arm.  I affirm both claims (and have explained why). So far, no problem.   Now add determinism and the theory of counterfactuals that we are assuming is correct -- Lewis's theory.  How is this supposed to yield a problem?  I've already shown that it doesn't raise a problem so far as my arm-raising is concerned; my affirmation of my ordinary ability to raise my arm doesn't commit me to any incredible ability to perform or cause miracles.  Why think it is different so far as my ordinary ability to make choices about arm-raising is concerned?

It isn't. A few minutes ago, I made no choice about arm-raising; I didn't even consider the matter.  If I had chosen to raise my arm, there would have been some difference in my mental state beforehand, a difference that  provided me with a reason for arm-raising that I didn't actually have, or at least a reason to start deliberating about raising my arm.  It is this earlier difference in mental state that would have been the divergence miracle.  My choice would not have brought about this earlier miracle -- the order of causation would have been the other way around.  And so my claim that I was able to make that choice doesn't commit me to the claim that I was able to perform miraculous acts or bring it about that miracles occur.

We can go on in this way as long as you like. 

Is this a vicious regress? No, because I'm not claiming, as part of my analysis of the ability to raise my arm (my ability to choose to raise my arm, and so on) that I have the ability to bring about the necessary conditions for the exercise of that ability.

The Consequence Argument and Lewis's Reply

The only serious argument for incompatibilism that I know is the Consequence argument due, most famously, to Peter van Inwagen.  (An Essay on Free Will, OUP, 1983.)

The version I will discuss is due to David Lewis.  ("Are We Free to Break the Laws?”, Theoria 47 (1981), 113-121)

He tells us to think of the argument as a reductio.  A  compatibilist is someone who claims that the truth of determinism is compatible with the existence of the kinds of abilities that we assume we have in typical situations in which we deliberate and make a choice.   Let’s call these ‘ordinary abilities’. The Consequence argument claims that if we suppose that a deterministic agent has ordinary abilities, we are forced to credit her with incredible abilities as well.

Here is Lewis's argument.

Pretend that  determinism is true, and that I did not raise my hand (at that department meeting, to vote on a proposal) but had the ordinary ability to do so.  If I had exercised my ordinary ability – if I had raised my hand -- then either the remote past or the laws of physics would have been different (would have to have been different). But if that’s so, then I have at least one of two incredible abilities – the ability to change the remote past or the ability to change the laws. But to suppose that I have either of these incredible abilities is absurd.  So we must reject the claim that I had the ordinary ability to raise my hand.

Van Inwagen doesn't object to Lewis's way of stating his argument.  On the contrary, he has said that Lewis's paper  is “the finest essay that has ever been written in defense of compatibilism – possibly the finest essay that has ever been written about any aspect of the free will problem”.  ("How to Think about the Problem of Free Will”, Journal of Ethics (2008) 12, 337-341).

Van Inwagen now agrees that the Consequence argument fails as a reductio.

However, he claims that it has nevertheless succeeded in  "raising the price" of compatibilism.  (Freedom to Break the Laws", Midwest Studies in Philosophy, 28 (2004), Blackwell, 334-350).

I disagree. I say that the argument neither succeeds as a reductio nor succeeds in  "raising the price" of compatibilism - that is, the price of commonsense  at a deterministic world.  What the argument does achieve -- at least on Lewis's articulation of it -- is a clear statement of the counterfactuals to which the compatibilist is committed. The argument is valuable for this reason.  It makes it clear that we need to understand counterfactuals in order to understand what's at stake in the free will/determinism debate. But as an argument for incompatibilism, it fails.