These theories, deontology, the moral rights theory, and utilitarianism, contradict one another. Moreover, they give conflicting (inconsistent) recommendations. It is hence not possible to hold them together, in a pursuit of moral truth.

Are there any good arguments in defence of moral nihilism? I think not.

We can be certain that, if there are conflicting views in different cultures, some of these views must be false. This may help us to transcend our own narrow cultural horizon.

These theories, deontology, the moral rights theory, and utilitarianism, contradict one another. Moreover, they give conflicting (inconsistent) recommendations. It is hence not possible to hold them together, in a pursuit of moral truth.

Being a moral realist I see normative ethics as a search of the truth about our obligations and a search of explanation; the idea is that moral principles can help us to a moral explanation of our particular obligations.

Different areas present us with possibilities to test different theories.

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.