Imagine you’re in a car crash and the only part of you that survives is your brain. Suppose your brain is transplanted into the body of a brain-dead patient. Does the person become you? Are you still alive? What if instead your brain is cut in half and transplanted into the bodies of two people. Are there now two of you?
These are the sorts of questions Derek Parfit asked during his career. He was one of the greatest moral philosophers of our time. He died last weekend, aged 74.
Derek Parfit wrote two significant books during his career, Reasons and Persons (1984) and On What Matters (2011). He argued that personal identity does not matter and this made him less selfish and concerned about his own death.
When I believed [that personal identity is what matters], 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.
When I believed [that personal identity is what matters], I also cared more about my inevitable death. After my death, there will be no one living who will be me. I can now redescribe this fact. Though there will later be many experiences, none of these experiences will be connected to my present experiences by chains of such direct connections as those involved in experience-memory, or in the carrying out of an earlier intention. Some of these future experiences may be related to my present experiences in less direct ways. There will later be some memories about my life. And there may later be thoughts that are influenced by mine, or things done as the result of my advice. My death will break the more direct relations between my present experiences and future experiences, but it will not break various other relations. This is all there is to the fact that there will be no one living who will be me. Now that I have seen this, my death seems to me less bad.
[Excerpt from Reasons and Persons copied from http://www.vox.com/science-and-health/2017/1/3/14148208/derek-parfit-rip-obit]
In On What Matters he argues for the existence of universal ethical truths. In the past philosophers have argued that no such ethical objectivism exists because it’s so hard to agree on what is right and wrong and much of our thinking on this topic has, in the past, been shaped by religion. However it’s no longer acceptable to use “God’s command” as an argument since we live in an increasingly secular world. Parfit argues for ethical objectivism from a purely secular perspective. If there are no moral truths, he says, then anything is permissible. Peter Singer writes a good review of his book on Project Syndicate. Here’s an excerpt:
One major argument against objectivism in ethics is that people disagree deeply about right and wrong, and this disagreement extends to philosophers who cannot be accused of being ignorant or confused. If great thinkers like Immanuel Kant and Jeremy Bentham disagree about what we ought to do, can there really be an objectively true answer to that question?
Parfit’s response to this line of argument leads him to make a claim that is perhaps even bolder than his defense of objectivism in ethics. He considers three leading theories about what we ought to do – one deriving from Kant, one from the social-contract tradition of Hobbes, Locke, Rousseau, and the contemporary philosophers John Rawls and T.M. Scanlon, and one from Bentham’s utilitarianism – and argues that the Kantian and social-contract theories must be revised in order to be defensible.
Then he argues that these revised theories coincide with a particular form of consequentialism, which is a theory in the same broad family as utilitarianism. If Parfit is right, there is much less disagreement between apparently conflicting moral theories than we all thought. The defenders of each of these theories are, in Parfit’s vivid phrase, “climbing the same mountain on different sides.”
Readers who go to On What Matters seeking an answer to the question posed by its title might be disappointed. Parfit’s real interest is in combating subjectivism and nihilism. Unless he can show that objectivism is true, he believes, nothing matters.
When Parfit does come to the question of “what matters,” his answer might seem surprisingly obvious. He tells us, for example, that what matters most now is that “we rich people give up some of our luxuries, ceasing to overheat the Earth’s atmosphere, and taking care of this planet in other ways, so that it continues to support intelligent life.”
I am interested in this because I became a vegan for ethical reasons. The other reasons for being vegan – environmental, health, financial – just reinforce my decision but they were not the motivating factor. Derek Parfit gave this talk at Oxford last year and in it he says,“It’s clear that we should become vegetarians if we aren’t already. That’s heavily overdetermined now and partly because cows produce 10% of global warming by emitting methane and we treat them terribly. That’s absolutely clear. Second, we shouldn’t have more than two children and we should know that if we don’t have any children that’s one way in which we’re doing a lot of good or of doing less harm. The children of we rich people add much more to global warming and thus to existential risks. “
He also, like Peter Singer, says we should all be giving 10% of our income to the poor.