📙 Reasons and Persons

Author: Derek Parfit

Full Title: Reasons and Persons

Highlights from March 8th, 2021.

Like my cat, I often simply do what I want to do. I am then not using an ability that only persons have. We know that there are reasons for acting, and that some reasons are better or stronger than others.
We are particular people. I have my life to live, you have yours. What do these facts involve? What makes me the same Person throughout my life, and a different Person from you? And what is the importance of these facts? What is the importance of the unity of each life, and of the distinction between different lives, and different Persons?
Philosophers should not only interpret our beliefs; when they are false, they should change them.
C implies that we should always try do whatever would make the outcome as good as possible. If we are disposed to act in this way, we are pure do-gooders. If we were all pure do-gooders, this might make the outcome worse. This might be true even if we always did what, of the acts that were possible for us, would make the outcome best. The bad effects might come, not from our acts, but from our disposition.
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.
I also believe that, even if we became convinced that Consequentialism was the best moral theory, most of us would not in fact become pure do-gooders.
Consider the question of how much the rich should give to the poor. For most Consequentialists, this question ignores national boundaries. Since I know that most other rich people will give very little, it would be hard for me to deny that it would be better if I gave away almost all my income. Even if I gave nine-tenths, some of my remaining tenth would do more good if spent by the very poor. Consequentialism thus tells me that I ought to give away almost all my income.
Collective Consequentialism is much less demanding. It does not tell me to give the amount that would in fact make the outcome best. It tells me to give the amount which is such that if we all gave this amount, the outcome would be best.
Can there be gaps in the continued existence of a physical object? Suppose that I have the same gold watch that I was given as a boy even though, for a month, it lay disassembled on a watch-repairer’s shelf. On one view, in the spatio-temporal path traced by this watch there was not at every point a watch, so my watch does not have a history of full physical continuity. But during the month when my watch was disassembled, and did not exist, all of its parts had histories of full continuity. On another view, even when it was disassembled, my watch existed.
Locke suggested that experience-memory provides the criterion of personal identity.
Locke claimed that someone cannot have committed some crime unless he now remembers doing so. We can understand a reluctance to punish people for crimes that they cannot remember. But, taken as a view about what is involved in a Person’s continued existence, Locke’s claim is clearly false. If it was true, it would not be possible for someone to forget any of the things that he once did, or any of the experiences that he once had. But this is possible. I cannot now remember putting on my shirt this morning.
Many Non-Reductionists believe that we are separately existing entities. On this view, personal identity over time does not just consist in physical and/or psychological continuity. It involves a further fact. A person is a separately existing entity, distinct from his brain and body, and his experiences. On the best-known version of this view, a person is a purely mental entity: a Cartesian Pure Ego, or spiritual substance. But we might believe that a person is a separately existing physical entity, of a kind that is not yet recognised in the theories of contemporary physics.
While I type this sentence, I am aware of the movements of my fingers, and can see the sunlight on my desk, and can hear the wind ruffling some leaves. What unites these different experiences? Some claim: the fact that they are all my experiences. These are the experiences that are being had, at this time, by a particular person, or subject of experiences. A similar question covers my whole life. What unites the different experiences that, together, constitute this life? Some give the same answer. What unites all of these experiences is, simply, that they are all mine. These answers I call the view that psychological unity is explained by ownership.
There are two unities to be explained: the unity of consciousness at any time, and the unity of a whole life. These two unities cannot be explained by claiming that different experiences are had by the same Person. These unities must be explained by describing the relations between these many experiences, and their relations to this Person’s brain. And we can refer to these experiences, and fully describe the relations between them, without claiming that these experiences are had by a Person.
Human beings have a lower brain and two upper hemispheres, which are connected by a bundle of fibres. In treating a few people with severe epilepsy, surgeons have cut these fibres. The aim was to reduce the severity of epileptic fits, by confining their causes to a single hemisphere. This aim was achieved. But the operations had another unintended consequence. The effect, in the words of one surgeon, was the creation of ‘two separate spheres of consciousness’.
This effect was revealed by various psychological tests. These made use of two facts. We control our right arms with our left hemispheres, and vice versa. And what is in the right halves of our visual fields we see with our left hemispheres, and vice versa. When someone’s hemispheres have been disconnected, psychologists can thus present to this Person two different written questions in the two halves of his visual field, and can receive two different answers written by this Person’s two hands.
One of the complications in the actual cases is that for most people, in at least the first few weeks after the operation, speech is entirely controlled by the right-handed hemisphere. As a result, ‘if the word “hat” is flashed on the left, the left hand will retrieve a hat from a group of concealed objects if the person is told to pick out what he has seen. At the same time he will insist verbally that he saw nothing.’
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.
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.
A similar objection claims that, in these actual and imagined cases, the result is not a single person with either a divided mind or two minds. The result is two different people, sharing control of most of one body, but each in sole control of one arm. Here too, I believe that this objection does not raise a real question. These are again two ways of describing the same, outcome.