I am trying to decide what profession to go into. What I mind is that I should act in a way which is best for reducing the unbearable suffering of some people. I want become a doctor. I would make a good doctor. But then an argument occurs to me: If I don't become a doctor, someone else, probably equally good, will do the job I would have done. Therefore, it doesn't matter what I do. Perhaps I should become a banker, and then I can give more to charity. Is there something wrong with the argument?