Reasons and Persons

by Derek Parfit

the Self-interest Theory, or S. This is a theory about rationality. S gives to each person this aim: the outcomes that would be best for himself, and that would make his life go, for him, as well as possible.

(S1) For each person, there is one supremely rational ultimate aim: that his life go, for him, as well as possible.

The cases worth discussing are of kind (b). In these cases it will be worse for me if I am purely self-interested, even if I succeed in never doing what will be worse for me. The bad effects come, not from what I do, but from my disposition, or the fact that I am purely self-interested.

Hedonists have long known that happiness, when aimed at, is harder to achieve. If my strongest desire is that I be happy, I may be less happy than I would be if I had other desires that were stronger. Thus I might be happier if my strongest desire was that someone else be happy.

Kate is a writer. Her strongest desire is that her books be as good as possible. Because she cares so much about the quality of her books, she finds her work rewarding. If her desire to write good books was much weaker, she would find her work boring. She knows this, and she accepts the Hedonistic Theory about self-interest. She therefore believes that it is better for her that her strongest desire is that her books be as good as possible. But, because of the strength of this desire, she often works so hard, and for so long, that she collapses with exhaustion, and is, for a period, very depressed.

These are the different versions of Consequentialism, or C. C’s central claim is (C1) There is one ultimate moral aim: that outcomes be as good as possible. C applies to everything. Applied to acts, C claims both (C2) What each of us ought to do is whatever would make the outcome best, and (C3) If someone does what he believes will make the outcome worse, he is acting wrongly.

(C4) What we ought subjectively to do is the act whose outcome has the greatest expected goodness.

(C5) The best possible motives are those of which it is true that, if we have them, the outcome will be best.

Utilitarianism. This theory combines C with the following claim: the best outcome is the one that gives to people the greatest net sum of benefits minus burdens, or, on the Hedonistic version of this claim, the greatest net sum of happiness minus misery.

There are many ways in which, if we were all pure do-gooders, this might have bad effects. One is the effect on the sum of happiness. On any plausible version of C, happiness is a large part of what makes outcomes better. Most of our happiness comes from having, and acting upon, certain strong desires. These include the desires that are involved in loving certain other people, the desire to work well, and many of the strong desires on which we act when we are not working. To become pure do-gooders, we would have to act against or even to suppress most of these desires. It is likely that this would enormously reduce the sum of happiness.

we may conclude that the avoidance of wrongdoing is a mere means.

We might call T directly collectively self-defeating when it is true that, if all of us successfully follow T, we will thereby cause our T-given aims to be worse achieved than they would have been if none of us had successfully followed T.

theory T directly collectively self-defeating when (i) it is certain that, if we all successfully follow T, we will thereby cause our T-given aims to be worse achieved than they would have been if none of us had successfully followed T, or (ii) our acts will cause our T-given aims to be best achieved only if we do not successfully follow T.

It is very often true that, if each rather than none does what will be better for himself, this will be worse for everyone.

We might become trustworthy. Each might then promise to do A on condition that the others make the same promise. We might become reluctant to be ‘free-riders’. If each believes that many others will do A, he may then prefer to do his share. We might become Kantians. Each would then do only what he could rationally will everyone to do. None could rationally will that all do E. Each would therefore do A. We might become more altruistic. Given sufficient altruism, each would do

(C6) An act benefits someone if its consequence is that someone is benefited more. An act harms someone if its consequence is that someone is harmed more. The act that benefits people most is the act whose consequence is that people are benefited most.

The First Mistake in moral mathematics is the Share-of-the-Total View. We should reject this view, and appeal instead to (C6).

(C7) Even if an act harms no one, this act may be wrong because it is one of a set of acts that together harm other people. Similarly, even if some act benefits no one, it can be what someone ought to do, because it is one of a set of acts that together benefit other people.

(The Fifth Mistake) If some act has effects on other people that are imperceptible, this act cannot be morally wrong because it has these effects. An act cannot be wrong because of its effects on other people, if none of these people could ever notice any difference. Similarly, if some act would have imperceptible effects on other people, these effects cannot make this act what someone ought to do.

(C10) When (1) the best outcome would be the one in which people are benefited most, and (2) each of the members of some group could act in a certain way, and (3) they would benefit these other people if enough of them acted in this way, and (4) they would benefit these people most if they all acted in this way, and (5) each of them both knows these facts and believes that enough of them will act in this way, then (6) each of them ought to act in this way.

(C11) When (1) the members of some group would make the outcome better if enough of them acted in some way, and (2) they would make the outcome best if all of them acted in this way, and (3) each of them both knows these facts and believes that enough of them will act in this way, then (4) each of them ought to act in this way.

If we cared sufficiently about effects on others, and changed our moral view, we would solve such problems. It is not enough to ask, ‘Will my act harm other people?’ Even if the answer is No, my act may still be wrong, because of its effects. The effects that it will have when it is considered on its own may not be its only relevant effects. I should ask, ‘Will my act be one of a set of acts that will together harm other people?’ The answer may be Yes. And the harm to others may be great.

At the collective level—as an answer to the question, ‘How should we all act?’—the Self-interest Theory would condemn itself. Suppose that we are choosing what code of conduct will be publicly encouraged, and taught in schools. S would here tell us to vote against itself. If we are choosing a collective code, the self-interested choice would be some version of morality.

In the Intertemporal Dilemma, I do better over time at each time only if at each time I do worse than I then could.

(R1) When M is self-defeating, we should all ideally do what will cause the M-given aims of each to be better achieved.

The number k has two special features: (1) If k or more contribute, each contributor is joining a scheme whose net effect is to benefit his own children. The children of each contributor will be benefited more than they would have been if no one had contributed. (2) If less than k contribute, any contributor’s children will be benefited less than they would have been if no one had contributed. (1) and (2) make k a plausible moral threshold above which each parent ought to contribute. We can claim (R2) In such cases, each ought to contribute if he believes that there will be at least k contributors.

(R3) When M is self-defeating, each of us ought to give no priority to those to whom he is M-related, if he believes that at least k others will act in the same way.

This suggestion is developed in the Deliberative Theory. This claims DP: What each of us has most reason to do is what would best achieve, not what he actually wants, but what he would want, at the time of acting, if he had undergone a process of ‘ideal deliberation’—if he knew the relevant facts, was thinking clearly, and was free from distorting influences.

(CP2) There is at least one desire that is not irrational, and is no less rational than the bias in one’s own favour. This is a desire to do what is in the interests of other people, when this is either morally admirable, or one’s moral duty.

We often act in ways which may seem to show that we are not biased towards the near: we bring pains into the nearer future, and postpone pleasures. The bias towards the future provides the explanation.

But the desire here comes first. We do not have to know whether we could make something true before we can want it to be true.

if we could, we ought not to be biased towards the future. In giving us this bias, Evolution denies us the best attitude to death.

Though our chief concern is our numerical identity, psychological changes matter. Indeed, on one view, certain kinds of qualitative change destroy numerical identity. If certain things happen to me, the truth might not be that I become a very different person. The truth might be that I cease to exist—that the resulting person is someone else.

Since strong connectedness is not transitive, it cannot be the criterion of identity.

We cannot defensibly believe that our identity involves a further fact, unless we also believe that we are separately existing entities, distinct from our brains and bodies. And we cannot defensibly believe that our identity must be determinate, unless we believe that the existence of these separate entities must be all-or-nothing.

When I imagine myself about to press the green button, it is hard to believe that there is not a real question whether I am about to die, or shall instead wake up again on Mars. But, as I have argued, this belief cannot be justified unless personal identity involves a further fact. And there could not be such a fact unless I am a separately existing entity, apart from my brain and body.

What is a fact must be possible. And it is a fact that people with disconnected hemispheres have two separate streams of consciousness—two series of thoughts and experiences, in having each of which they are unaware of having the other. Each of these two streams separately displays unity of consciousness. This may be a surprising fact. But we can understand it. We can come to believe that a person’s mental history need not be like a canal, with only one channel, but could be like a river, occasionally having separate streams. I suggest that we can also imagine what it would be like to divide and reunite our minds.

Because we ascribe thoughts to thinkers, it is true that thinkers exist. But thinkers are not separately existing entities. The existence of a thinker just involves the existence of his brain and body, the doing of his deeds, the thinking of his thoughts, and the occurrence of certain other physical and mental events. We could therefore redescribe any person’s life in impersonal terms. In explaining the unity of this life, we need not claim that it is the life of a particular person. We could describe what, at different times, was thought and felt and observed and done, and how these various events were interrelated. Persons would be mentioned here only in the descriptions of the content of many thoughts, desires, memories, and so on. Persons need not be claimed to be the thinkers of any of these thoughts.

On the Cartesian View, a particular mental event occurs within a particular life solely in virtue of its ascription to a particular Ego. We can deny that the topography of ‘Mental Space’ is given by the existence of such persisting Egos. We can claim that a particular mental event occurs within some life in virtue of its relations to the many other mental and physical events which, by being interrelated, constitute this life.36

claim that a person is not like a Cartesian Ego, a being whose existence must be all-or-nothing. A person is like a nation.

I suspect that reviewing my arguments would never wholly remove my doubts. At the reflective or intellectual level, I would remain convinced that the Reductionist View is true. But at some lower level I would still be inclined to believe that there must always be a real difference between some future person’s being me, and his being someone else. Something similar is true when I look through a window at the top of a sky-scraper. I know that I am in no danger. But, looking down from this dizzying height, I am afraid. I would have a similar irrational fear if I was about to press the green button.

What I fear will be missing is always missing.

Ordinary survival is about as bad as being destroyed and Replicated.

Nagel once claimed that it is psychologically impossible to believe the Reductionist View. Buddha claimed that, though this is very hard, it is possible. I find Buddha’s claim to be true. After reviewing my arguments, I find that, at the reflective or intellectual level, though it is very hard to believe the Reductionist View, this is possible. My remaining doubts or fears seem to me irrational. Since I can believe this view, I assume that others can do so too. We can believe the truth about ourselves.

Is the truth depressing? Some may find it so. But I find it liberating, and consoling. When I believed that my existence was a such a further fact, I seemed imprisoned in myself. My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air. There is still a difference between my life and the lives of other people. But the difference is less. Other people are closer. I am less concerned about the rest of my own life, and more concerned about the lives of others.

Is loving a person basically the same as loving that person’s body?

Fusions, like marriages, could be either great successes, or disasters.

Here again, we want connectedness, not mere continuity.

We are incapable, while we are in love, of acting as fit predecessors of the next persons who, when we are in love no longer, we shall presently have become

It is not because other people are dead that our affection for them grows faint, it is because we ourself are dying.