A fourteen-year-old girl wants a baby. If she has one, she will be unable to give him a good start in life. If she has her first baby at twenty-five instead, she will be able to give him a better start in life – but that would be a different baby. So whom is she harming by giving birth at fourteen? No one. Not the baby as long as his life is worth living.

Suppose we who are living now decide to ignore global warming, with the result that the lives of future people are much harder. It would seem that we have made things worse for those future people. But, in fact, as long as their lives are worth living this is not the case – because if we had acted differently, the world would have been different, and those particular people would have never existed (in the same way that if cars had not been invented most people alive today would never have never been born.) So, although we have made the world worse in the future, we have made life worse for no one.

Mindf*&k enough?

These are the brilliant constructs of Derek Parfit, who specializes in problems of personal identity, rationality and ethics, and the relations between them. I discovered through a recent New Yorker article. (Sorry, only subscribers. Get one already. Just this mindf*&k is worth it.)

(Clearly, these ideas are just buzzing with moral problems. Parfit is aware of and concerned by them.)

What is death?

“My death will break the more direct relations between my present experiences and future experiences, but it will not break various other relations.”

Some people will remember you. Others may be influenced by your work, your words, whatever you communicated or act upon your advice. Memories that connect with your memories, thoughts that connect with your thoughts, actions taken that connect with your intentions, will persist after you’re gone, just inside different bodies.

“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 be less bad.”

Read his books.

Derek Parfit might just be the genius we’ve all been waiting for.