I am indeed a moral realist.

How could it be that I had a legal obligation to kill people I did not know, and who did certainly not consent to it, while my father's doctor could not help my father to die when my farther asked for it? My consternation brought me to moral philosophy and a life-long search for an answer to the question when and why we should, and when we shouldn't, kill.

We should not accept moral nihilism unless we find strong arguments to do so.

My conjecture is that most people will refuse to let go, even when their lives have become boring (at least in comparisons with possible lives lived by new generations). If this happens, there will eventually be no room for new generations. A kind of collective irrationality will lead to a bleak life for the last generation that decides to stay around. Unless we put and end to the human race (through global warming, for example), before this happens, individual egoism will block the path to a better world.

The Chinese are generally speaking much more reluctant than Westerners to killing as a means to the rescue of lives.

Once we realise that utilitarianism comes with the idea of blameworthy rightdoing (such as when you push a big man onto the tracks in order to save five lives) and blameless wrongdoing (such as when you don't push a big man onto the tracks in order to save five lives), then utilitarianism all of a sudden appears to give the right answers.

We own ourselves. This is the core of a libertarian theory of rights. But on this theory, while we are at liberty to kill ourselves (regardless of the consequences of others), we are not allowed to kill others, not even if this means that there we be fewer murders in the future, totally speaking.