Where does morality come from? We seem to feel what’s right and what’s wrong in our very bones. Even babies, before they can speak, have been shown to have a nascent moral sense and a definite preference for good over evil. Did God instill this capacity for moral judgement in us? According to the Bible, God forbade us this capacity when he told Adam and Eve not to eat of the tree of knowledge of good and evil. Presumably God wanted humans to receive moral knowledge from God’s commands only, but, as we now know, that didn’t work out too well.
Consequently, there have been as many interpretations of God’s commands as there have been peoples and religions. In fact, there is no prospect of getting beyond interpretation, because even people who claim to have gotten instruction directly from God are in competition with others who also claim this, but give radically different directives.
What about the idea that morality evolved? Charles Darwin, the originator of the theory of natural selection, in his book The Descent of Man, argues that morality could have evolved by “group selection”, where human groups who followed moral rules were more cohesive and stronger, and therefore bested groups who didn’t. This is an improvement over the idea of natural selection of individuals, which is the basis of Darwin’s overall theory, since “survival of the fittest” fundamentally contradicts morality. If you can’t see this, think about the fact that widows and orphans, the sick, and the lame, i.e., those who are most likely to perish, are encouraged to do so under “Social Darwinism”, something even Darwin abhorred.
It’s interesting that not long after Darwin died, his most loyal defender, Thomas Huxley, gave a famous lecture in which he contradicted the idea that morality could have originated from natural selection. Huxley compared morality to a well-tended garden, which receives its productivity from the constant attention and effort of the gardener to cast out the weeds, and encourage the beneficial plants. Humans cultivate productive crops whereas nature gives us weeds. Doing good and avoiding evil takes constant effort.
Moral systems do not exist outside human society because animal societies are strictly organized according to dominance relations. The dominant male produces the most progeny - that’s survival of the fittest. Whereas in most human societies the vast majority of human families are monogamous, Monogamy destroys the alpha male’s monopoly over procreation. Indeed, in nomadic hunter gatherers, the first human cultures, male dominance type behaviours, such as boasting, threatening, and violence were actively discouraged, and sharing food was encouraged - evidence that the origins of human morality and monogamy were linked, and did not naturally evolve, but were consciously chosen by the first humans.