The concept of free choice is perfectly coherent and easily stated. Free choice, to the extent that it is real, would be an uncaused cause. It is the opposite of what we call an epiphenomenon. A good example of the latter is the reflection of a tree in a pond: if you cut down the tree, the reflection disappears; but if you drop a rock on the reflection, the tree is unmoved. An epiphenomenon is all effect and no cause. If free choice exists, the present self has a genuine choice between (at least) two alternatives and creates a future that would not otherwise have existed. If we decide to pick up hitchhikers as an act of charity at a greater risk to our lives, the world will be different: more hitchhikers will get to their destinations quicker and some extra lives will be lost. Free choice breaks the flow of the world from past to future and thus the result is what philosophers call metaphysical discontinuity.
Selves All the Way InThe word for someone who holds Flynns views on free will is libertarian, which is confusing, because there is also a political leaning called libertarianism, and this Flynn is most certainly not hes a passionate Social Democrat. Sam Harris, on the other hand, is a political libertarian but a metaphysical hard-determinist, which is to say he rejects free will outright. I mention Harris because he recently wrote a little book titled Free Will. It was available for free online for a short while, but Im afraid I missed it, and the libraries in Dunedin havent got hold of a copy yet. So I can only quote directly from the bits that made it into the Amazon.com preview, and hope the related posts on Harriss blog dont miss anything important.
Free will is an illusion. Our wills are simply not of our own making. Thoughts and intentions emerge from background causes of which we are unaware and over which we exert no conscious control. We do not have the freedom we think we have.
It should be clear that this kind of uncausedness is a lousy basis for free will, but some people have hung their hopes on it. An otherwise excellent book, which has helped demystify quantum physics for me to a great degree, identifies free will with indeterminacy:
This is an old problem in a new guise. In the heyday of classical physics it seemed that every physical event in the universe must be determined absolutely and predictably from previous events, because the rule of cause-and-effect was inviolable. But then everything in the universe must have been preordained from the outset, so that the absolute determinism of classical physics apparently negated the possibility of free will. No-one ever resolved that conundrum.
Something can be indeterminate and not worthy of praise or blame. A random event like an electron jump cannot be praised or blamed because no present self exists faced with open alternatives and freely choosing between them. The same is true of a clock. The existence of a present self of this sort is the crux of the matter. You do not praise or blame a Mexican jumping bean simply because it is unpredictable.
But a random event does not fit the concept of free will any more than a lawful one does, and could not serve as the long-sought locus of moral responsibility. We would not find someone guilty if his finger pulled the trigger when it was mechanically connected to a roulette wheel; why should it be any different if the roulette wheel is inside his skull? The same problem arises for another unpredictable cause that has been suggested as the source of free will, chaos theory, in which, according to the cliché, a butterflys flutter can set off a cascade of events culminating in a hurricane.
Either we dispense with all morality as an unscientific superstition, or we find a way to reconcile causation (genetic or otherwise) with responsibility and free will. I doubt that our puzzlement will ever be completely assuaged, but we can surely reconcile them in part. Like many philosophers, I believe that science and ethics are two self-contained systems played out among the same entities in the world, just as poker and bridge are different games played with the same fifty-two-card deck. The science game treats people as material objects, and its rules are the physical processes that cause behaviour through natural selection and neurophysiology. The ethics game treats people as equivalent, sentient, rational, free-willed agents, and its rules are the calculus that assigns moral value to behaviour through the behaviours inherent nature or its consequences.
Free will is an idealization of human beings that makes the ethics game playable. Euclidean geometry requires idealizations like infinite straight lines and perfect circles, and its deductions are sound and useful even though the world does not really have infinite straight lines or perfect circles. The world is close enough that the theorems can be usefully applied. Similarly, ethical theory requires idealizations like free, sentient, rational, equivalent agents whose behaviour is uncaused, and its conclusions can be sound and useful even though the world, as seen by science, does not really have uncaused events. As long as there is no outright coercion or gross malfunction of reasoning, the world is close enough to the idealization of free will that moral theory can meaningfully be applied to it.
But the answer cannot be that there is a free, sentient, rational agent somewhere within the brain. Even if that were so if the frontal cortex, say, turned out to act as an agent in its own right that would not count as an explanation. And this is where Flynn goes wrong, and where the third alternative (besides determinism and jumping-bean indeterminacy) reveals itself for the nonsense it is. Last time, I asked you to imagine explaining the functioning of a cars engine by positing a little car running on a treadmill under the bonnet. Flynns present self is just such a little car. If an entity can only be a free-willed, choosing agent by having a smaller free-willed choosing agent, its present self, inside it, then for the present self to be a free-willed choosing agent it must have its own little present self making choices inside it; and this must have a still smaller self, and so, literally, ad infinitum. It must be selves all the way in. If at any point the regress stops, then the innermost self must be either a deterministic system or a jumping bean. If it is, nevertheless, an agent with free will, then it is not true that a free-willed agent cant be made up solely of deterministic and/or jumping-bean parts. If it isnt an agent with free will, then on Flynns own logic neither are any of the onion-layers of larger selves around it, including the whole human being.
Actually, we know for a fact that the brain doesnt go all the way to being an ideal free sentient agent, because of the work of a neuroscientist named Benjamin Libet. He attached EEG electrodes to his subjects heads and sat them in front of a display with a rapidly-circling dot. They were to perform a small, one-hand action (pressing a button, twitching their wrist, flicking a finger; Libet varied this part of the experiment) whenever they felt like it, and report where on the screen the dot was when they decided to do it. Their reports showed that they became conscious of the decision a ponderous 0.3 to 0.5 seconds after their brain actually initiated the movement. The present self turned out to be merely a commentator after the fact.
The philosopher Daniel C. Dennett discusses the implications in detail in Freedom Evolves. Anyone who follows this kind of stuff will know that name. Dennett is the most prominent of all the compatibilists, and no serious thinker on free will, consciousness, or the self can afford to ignore him. Those of you whove read Freedom Evolves and its predecessor Elbow Room, and since youre here reading a blog about free will Id imagine thats quite a large percentage of you, will recognise his influence throughout the rest of this essay. According to Dennett, there are quite a number of hypotheses consistent with Libets data, all of them variations on the theme of Consciousness takes time. However,
Libets data do rule out one hypothesis, which might have been our favourite: Self-contained You, according to which all the brains chores are gathered into one compact location, where everything could happen at once in one place vision, hearing, decision-making, simultaneity-judging... With everything so handy, the timing problem couldnt arise: A person, a soul, could sit there and make free, responsible decisions and be simultaneously conscious of making them, and of everything else going on in consciousness at the time. But there is no such place in the brain.
[Dennett] rejects the reality of radical free will on the grounds that it cannot be reconciled with scientific explanation. But that does not justify salvaging science at the expense of free will. Why assume that we must reject the reality of free choice if that renders part of reality beyond scientific explanation? Why not assume the reverse: that we must recognise a limit on science if uncaused causes are part of reality. Dennett has a field day demolishing those who try to fit free choice into some niche created by scientific explanation (such as indeterminacy). They are mistaken to try. Science excites our admiration because of the wonderful explanations it has given us about the world thus far. But no-one has evidenced the hypothesis that all of reality is susceptible to scientific explanation.
Even if you believe that every human being harbours an immortal soul, the problem of responsibility remains; I cannot take credit for the fact that I do not have the soul of a psychopath.
To Do What I Want Any Old TimeThe idea of having no control over our actions is scary, and for good reason. Imagine being locked in a cell, or tied to a chair, or surrounded by enemies with no escape route such scenarios are the stuff of thrillers and horrors. Animals know this fear too, and shun enclosure. Natural selection gave us this instinct fundamentally because the universe doesnt care about us. We are fragile. There are many more configurations of matter that harm us than benefit us, and nearly all possible pathways our existence could take will bump into them. The only things that do have our interests at heart are ourselves. If we are pinned to one spot by a rockfall the universe will not bring us water. If we are encircled by lions the universe will not turn their attacks aside. The freedom instinct is a survival necessity in a Godless world.
Im afraid I have to emphasize this, because of one of the most common contexts in which we hear the phrase free will. Christians say that the world was once perfect, and as part of that perfection God gave us the gift of free will, which we misused by disobeying him and turning to sin. If youve come here looking for support for this doctrine, I can offer you nothing. If the world were ever perfect, if it once contained nothing that could harm us, then the ability to change it away from that perfection would have been a curse, not a gift.
Free will is often explained as follows: If we have it, then we could have chosen to do something else, instead of what we actually did do. Thats why the logic of determinism vs. indeterminism seems so damning. If our actions are deterministic, then we couldnt have done anything else; and if theyre indeterministic, then we could have done something else, but we couldnt have chosen it. We need to realize that this is not as straightforward as it seems.
A teenage boy, bored and anxious to prove his courage and agility, takes his skateboard up to the roof of an apartment building. Trundling around at low speed, he wobbles and stumbles off the board. Annoyed, he kicks it. It whizzes off to the other side of the roof, and there does not stall in the gutter as he had intended, but, to his horror, rattles over the edge and describes a neat parabolic arc towards the street below.
Now, any statement that some event could have happened differently must be contingent on an if... If the boy hadnt kicked the skateboard, it wouldnt have gone off the roof. But then, if the gutter had been deep enough to catch its wheels and stall it, it wouldnt have off the roof. Either way, if something had been different from the way it was, the skateboard wouldnt have fallen. In reality, the skateboard did fall. The statements The boy did not kick the skateboard and The skateboard stalled in the gutter are both false. I dont see what it can mean, philosophically, to say that the first statement is a realer, more live, or more present falsehood than the second, simply because the first one describes a choice and the second the trajectory of a physical object.
Ive said elsewhere that determinism is not the same thing as fatalism. In fact, its quite close to being the opposite. Granted, once the skateboard is over the edge, you might say it was fated to fall, in that nothing realistic can change the fact that its going to end up arriving at ground level with great force. But before it went over the edge, any number of things could have prevented that rubble, weeds growing out of cracks, pipes left by builders, a less well-aimed kick. Some possible paths at that point would have taken the board over the edge, and as it turned out one did; other possible paths would not have. Because the skateboards path is determined by the moment-by-moment events unfolding, the end of its trajectory is not set in stone. A different set of moment-by-moment events would have had a different outcome.
There is a difference between a choice and a regular old physical event, but its not that the choice really could have gone the other way in some sense that the physical event couldnt have. Unlike other events, a choice is aimed at some future outcome. The universe doesnt care what happens to us, but we do, and we hope to adjust our circumstances to be better for us. An intentional or deliberate action that is, a choice is one that occurs as a result of a conscious calculation of the agents interests.
That, I suggest, is what we really want free will for. Conceptually, its more complex than you might expect. You cant instruct a computer to follow the best course of action, because it doesnt know what the best course of action is not even if you spell out what outcome counts as best, because that still doesnt tell it which actions will lead towards that outcome. How might an agent build a road-map towards its goals? I can think of at least six ways:
- Trial and error Many people still have to resort to this when plugging a memory-stick into a USB port. Only one of the two possible orientations works, and its often hard to remember which one. To program this into a computer, you would need to write instructions on what counts as a right result, and what counts as an error. Youd also need to give it some way of figuring out exactly which choice it was that caused the error, and how far it needs to backtrack, and that, too, is more complicated than it sounds.
- Past trial and error I dont have trouble with my USB stick, because Ive memorized the fact that the side with the brand name on is the top. Most simple interactions with technology depend on remembering past trials, especially those that depend on turning something one way or the other (taps, car keys, screws...) Given a computer that could do trial-and-error in the first place, adding a memory database wouldnt be all that complicated, I suppose.
- Imagined trial and error You lock your car in the garage because you can imagine what would happen if you didnt. Often done with technological aids, such as pen and paper, when it gets too complex for the unaided brain, this is one of the major operations of what we call reason. I do not expect to see desktop computers doing this any time soon, but not because it cant be executed algorithmically. On the contrary, I have myself written a Sudoku game which employs it in a small way. It has to imagine the set of possible answers when choosing which squares to reveal as clues because, being a puzzle, it mustnt show the user what its doing. Usually, for a computer, the information space that constitutes its imagination is also its real world that the user is going to interact with. We who have to deal with the external world, where failure can be costly, eliminate the more disastrous options by running through the problem in the information space in our heads first.
- Instruction from a person who knows either someone who has learned by one of the methods above, or someone who has been instructed by someone else who has learned by one of the methods above, or... lengthen the line indefinitely. This is how I learned to write computer programs, to speak French and te Reo Māori, and to eat with a knife and fork, though of course the other forms of trial and error came into it too. All computers might be said to do this, but of course the question then is making sure the instructor really knows what they claim to know.
- Instruction from a group of people whose collective experience amounts to trial and error Its said that the ancient Celts revered the oak and maintained sacred groves that were never to be felled. Oaks make an impractical orchard tree they take decades to grow to maturity but they also survive harsh weather that might kill crop plants, and acorns are nutritious if somewhat bitter to taste. Did the Celts study the life cycle of the oak tree scientifically over centuries before choosing it as their sacred tree? Its unlikely. Its equally unlikely that any one person could have discovered it by trial and error, because growing a new grove for a second trial would take up most of their lifetime. Assuming they really did revere the oak (that story may be nothing but a misinterpretation of the word druid), its more plausible that tribes who happened to preserve their oaks for any reason were well-placed, after freak storms, to conquer tribes who had cut theirs down and were left with no food. The trials and errors are distributed among many different subjects, but as long as they have some way to pass the custom on, knowledge accumulated in this way will turn out to be useful more often than chance, or a rational examination of the peoples own theory of why it works, would predict. I suspect that many of our most basic cultural practices have been wrung through this process.
- Inheritance of instinct from ancestors whose collective experience amounts to trial and error This is the longest, slowest way to acquire knowledge, but also the one that requires the least cognitive apparatus. Its even simpler than trial and error, because you dont even need a capacity to tell right from wrong; those who get it wrong die without leaving offspring, and do not perpetuate their error to the next generation. The earliest version of my Sudoku program was intended to generate puzzles for print, not for playing in real time, and all it did was to generate eighty-one random numbers from 1 to 9, make a thousand copies with a few changes in each, pick the one with the fewest errors, and then go back to the thousand-copies step unless the number of errors was zero. It zipped along quite quickly until you got down to 16 errors, I think it was, at which point it slowed to a crawl; you ended up with a valid Sudoku grid about twenty minutes later. Natural selection seldom squares away those last few errors, but its exacting enough to have produced the cognitive systems the other five methods depend on, and they can cover the remaining ground.
But in what sense was that baseball going to hit you smack in the face? You dodged it; you were caused to dodge it by the elaborate system evolution has built into you to respond to photons bouncing off incoming missiles on certain trajectories. It was never really going to hit you precisely because it caused your avoidance system to go into action...
The very idea of changing an outcome, common though it is, is incoherent unless it means changing the anticipated outcome... The real outcome, the actual outcome, is whatever happens, and nothing can change that in a determined world or in an undetermined world!
The popular conception of free will seems to rest on two assumptions: (1) that each of us could have behaved differently than we did in the past, and (2) that we are the conscious source of most of our thoughts and actions in the present... both of these assumptions are false.
The problem is not merely that free will makes no sense objectively (i.e. when our thoughts and actions are viewed from a third-person point of view); it makes no sense subjectively either. It is quite possible to notice this through introspection. In fact, I will now perform an experiment in free will for all to see: I will write anything I want for the rest of this book. Whatever I write will, of course, be something I choose to write. No one is compelling me to do this. No one has assigned me a topic or demanded that I use certain words. I can be ungrammatical if I pleased. And if I want to put a rabbit in this sentence, I am free to do so.
But paying attention to my stream of consciousness reveals that this notion of freedom does not reach very deep. Where did this rabbit come from? Why didnt I put an elephant in that sentence? I do not know. I am free to change rabbit to elephant, of course. But if I did this, how could I explain it? It is impossible for me to know the cause of either choice. Either is compatible with my being compelled by the laws of nature or buffeted by the winds of chance; but neither looks, or feels, like freedom. Rabbit or elephant? Am I free to decide that elephant is the better word when I just do not feel that it is the better word? Am I free to change my mind? Of course not. It can only change me.
Youre Not the Boss of Me NowThe second main thing that scares us, when we consider life without free will, is the idea of our behaviour being predictable or controllable. We want to control ourselves, we dont want others to control us; and we know that if they could predict our actions perfectly they would be able to control us. But if our decisions come from a web of purely deterministic neuron-firing events in our brains, then surely in principle someone could plot out that web and predict what were going to do.
In principle? Perhaps. But that in principle is deceptive. Conways Game of Life is purely deterministic, governed by a very short list of extremely simple rules far, far simpler than those of the brain. Now follow the link and see if you can predict its behaviour in anything remotely like real-time. Not easy, is it? Still, I suppose its all a matter of computer power. Theres a more fundamental difficulty for anyone setting out to do mind-control.
Two words sum up the obstacle. They are not free will or human spirit or scientifically inexplicable or spooky, paranormal or any word pair in that general area of the cloud of English word-associations. They are recursive self-awareness. Self-awareness means that a human mind can contemplate its own states, and their likely consequences, and weave them into its plans for future action; recursive means that self-awareness itself is among the things it can become aware of. To which I imagine your reaction is quite likely What? Thats all? The consequences are not immediately obvious. Anyone trying to predict exactly what your brain is going to do next, will need to account for your knowledge of their prediction. Having accounted for it, they then need to account for your knowledge of the accounting. Having accounted for that... you get the idea. The moment you figure out what they know about you, that knowledge becomes part of the chain of causes for your actions. Chestertons game of Cheat the Prophet can easily be adapted for day-by-day or minute-by-minute gameplay:
The human race, to which so many of my readers belong, has been playing at childrens games from the beginning, and will probably do it till the end, which is a nuisance for the few people who grow up. And one of the games to which it is most attached is called, Keep tomorrow dark, and which is also named (by the rustics in Shropshire, I have no doubt) Cheat the Prophet. The players listen very carefully and respectfully to all that the clever men have to say about what is to happen in the next generation. The players then wait until all the clever men are dead, and bury them nicely. They then go and do something else. That is all. For a race of simple tastes, however, it is great fun.
As a bonus, recursive self-awareness illuminates another puzzle: what are decisions for? What do they add to our understanding of human action? It doesnt look like a puzzle, until someone brings it up. Why decide to do things? Why not just do them? What does the decision add to the picture? We can certainly do things without deciding to do them I dont decide what to do with my foot every time I take a step, unless the surface Im walking on is somehow hazardous. We decide when the action requires conscious deliberation. But again, why does there have to be a moment of decision in between the deliberation and the act? I suggest its to avoid creating chaotic loops with our own recursive self-awareness. As we go through the act, instead of contemplating our own thoughts about our thoughts about our thoughts to figure out what were doing next, and wandering in circles and falling on our faces, we remember our decision, stick to it, and get our daily tasks done. If the alternative sounds unlikely, try deciding what you will think for the next two minutes, instead of what you will do. See how long it takes before a random thought pops into your head. Since thought, unlike action, is consequence-free on the timescale of seconds, natural selection didnt provide us with a decision-commitment subroutine for it.
Wont Be Held ResponsibleAs weve already seen, our actions are aimed at our interests. That deflates a couple of objections commonly put forth in favour of the traditional concept of free will. Why bother reasoning with anyone if they dont have free will? Because, logically, their actions can be altered by providing information relevant to the calculation of their interests. What good is it to hold people responsible for what they do? Because their actions can likewise be altered by adjusting their interests with rewards and punishments (social as well as official). But usefulness is one thing, and rightness is another.
I signed off Imponderable I with a set of unanswered questions, which boiled down to: How can anybody be held responsible for anything? Because my theory of morality is in a bit of a bind if they cant. You might not blame someone who isnt responsible, but you wouldnt trust them either; and trust, youll recall, is in my view the whole basis of moral reasoning. Dennett, as usual, has an answer.
Arent we headed toward a 100 percent medicalized society in which nobody is responsible, and everybody is a victim of one unfortunate feature of their background or another (nature or nurture)? No, we are not, because there are forces not mysterious metaphysical forces, but readily explainable social and political forces that oppose this trend, and they are of the same sort, really, as the forces that prevent the driving age from rising to, say, thirty! People want to be held accountable. The benefits that accrue to one who is a citizen in good standing in a free society are so widely and deeply appreciated that there is always a potent presumption in favour of inclusion. Blame is the price we pay for credit, and we pay it gladly under most circumstances. We pay dearly, accepting punishment and public humiliation for a chance to get back in the game after we have been caught out in some transgression.
Lets tackle the question from the easy end. When is somebody not responsible for something happening? Am I responsible for Pope Benedict resigning, or Hugo Chávez dying? Of course not, I didnt cause either one. For Entity A to be responsible for Event X, it must be the case that Entity A caused Event X.
I breathe air, returning it to the atmosphere with a little more carbon dioxide than it had before I got hold of it. I cause the carbon dioxide; am I responsible for it? No, Im not, because I cannot choose to stop breathing, or not for more than a minute or two at a time. For Entity A to be responsible for Event X, it must be the case that Entity A could have chosen not to cause Event X. And so we return to where we started. What does it mean to say that one could have chosen otherwise?
(Well, hypothetically I could choose not to breathe after all, as long as I was comfortable with dying. If Im not responsible for the consequences of my breathing, then it must be because its somehow not reasonable to expect me to choose to kill myself. Exactly what constitutes reasonable is an interesting question, but one that can wait for another time.)
Remember the teenagers skateboard, hurtling off the roof. If it hits someone and seriously injures them, we would hold him responsible, but less so than if he had lain in wait and intentionally flung it at them. Whats the difference? Recall, a deliberate action is one that follows a conscious calculation of the agents interests. A careless action might also be based on an assessment of the agents interests, but we would judge that the assessment process had been prematurely curtailed in this case, the teenager did not consider the skateboards potential for falling off the roof before kicking it. We hold him responsible for his thoughtlessness because we judge that that came from a calculation of another of his interests, namely his self-image as a powerful, decisive person. The connection with responsibility should be obvious: logically, the actions most appropriately altered by adjusting the agents interests are those performed under conscious contemplation of said interests.
All the easy parts aside, we must now face the could have done otherwise problem head-on. There is something, after all, in Pinkers separation of the science and ethics games. Responsibility is not part of the science game. We do not expect to find it in the laboratory at the cellular and brain-tissue scales studied by neuroscientists. It is a property that pertains to real-time social interaction between human beings, where (besides the fact that we dont have electrodes and fMRI scanners to play with) the other players are responding to us just as fast as we are responding to them. If we were to plot out the trajectories of every neurotransmitter molecule, and every calcium and sodium ion, in one anothers brains, after the fact and with no interference from the person concerned, we might well find there was only one outcome that didnt break a law of physics somewhere. But we dont have that kind of access to anyones neurons, which puts that information off-limits in the ethics game. Even if we did have an iPhone app (or such-like) for following neural activity in real-time, we are still impinging mutually on one anothers lives, and that means our future choices are screened behind recursive self-awareness. The proper truth-test is not Could you have chosen something else, given the same initial conditions down to the position of the last atom? It is Could you have chosen something else, having calculated your interests differently, given the same relevant conditions as best we can discern them in real-time?
Harris argues that responsibility-based ideas about justice are dangerous at best:
False beliefs about human freedom skew our moral intuitions and anchor our system of criminal justice to a primitive ethic of retribution.
However, this theory of will does not suit all theoretical moral purposes. As I said before, if you have come here looking for support for the Christian concept of free will, I have nothing to offer you. Recursive self-awareness would not screen our brains from an all-knowing God. From Gods point of view, we do not have free will; we do precisely what he always knew and (as our creator) intended we should do. This model of free will does not, therefore, provide a loophole out of the problem that a supposedly good, supposedly all-powerful God supposedly created a world with evil in it.
Some Christians explain the invisibility of God with reference to free will as well: he wanted us to love him freely, they say, but hes so awesome that if we could see him wed be compelled to do it. The same Christians will also say that the consequence of not loving God is an eternity in hell. But since free will is a matter of being able to act on ones interests, withholding information critical to assessing those interests does not preserve it but derails it. And do you remember the scene in The Lord of the Rings when Gandalf was imprisoned on the roof of Orthanc? Or was he imprisoned? He was free to jump off at any time, after all. The dreadful consequences of doing the wrong thing (absent a friendly eagle) made this freedom a sick joke. Same with hell, I would say.
Who Am I?Do we have free will? Not in the traditional sense, the Christian sense, the sense Flynn describes. But it seems perverse to insist on that, when we do have so many of the things we think we want free will for. We can pursue our own interests and avoid harm; our choices do have consequences; choosing something else would have different consequences unless we insisted on God-like precision in specifying exactly what conditions satisfied the hypothetical Starting from the same beginning situation... That being so, we can formulate a meaningful truth-test for responsibility (which, yes, would crumble given God-like knowledge, but we have not been given God-like knowledge). Moral reasoning and moral sanctions can dissuade other human beings from harming us or others. But I have saved Harriss subtlest counter-argument for last.
...am I responsible for the fact that it has never once occurred to me that I might like to be a surgeon? Who gets the blame for my lack of inspiration? And what if the desire to become a surgeon suddenly arises tomorrow and becomes so intense that I jettison my other professional goals and enroll in medical school? Would I that is, the part of me that is actually experiencing my life be the true cause of these developments?
There is an organism called Toxoplasma gondii which lives parasitically in the brains of mice. It does not harm them directly, but it has a dramatic and lethal effect on their behaviour: an infected mouse, faced with a cat, will run towards it instead of fleeing. This is because the sexual phase of Toxoplasmas life-cycle can only take place in the digestive tract of a cat. Toxoplasma infects humans as well. It doesnt drive us to suicide, because we are seldom preyed on by cats; but its easy to imagine a similar organism inspiring, say, an irresistible desire to swim with great white sharks. Now, obviously if mice could speak, they would say that Toxoplasma caused them to act contrary to their own interests. But an infected mouse might retort that its interests had changed that cat-fearing me (its past self) was some other mouse, no longer the real me, and that if it felt that blissful proximity to a cat was worth paying for with its life, that would be its own business. Dont laugh too hard; some people with life-threatening behavioural disorders (such as anorexia or tobacco addiction) make exactly equivalent statements.
Whats my answer? Who is I? What is the self? Once again, Im going to have to defer the question. The Self will be the subject of Imponderable III.