Science, by itself cannot, supply us with an ethic.
Science, by itself, cannot supply us with an ethic. It can show us how to achieve a given end, and it may show us that some ends cannot be achieved.
I can only say that, while my own opinions as to ethics do not satisfy me, other people's satisfy me still less.
Humanistic ethics is based on the principle that only humans themselves can determine the criterion for virtue and not an authority transcending us.