We spend a lot of energy arguing about what is right or wrong, but how many of us have stopped to ask what morality is?
Do the principles of morality exist apart from living beings? 2 + 2 would equal 4 even if there were nobody around to add the numbers, but would Do unto others as you would have them do unto you make any sense if there were no others and no you? Right away we see that morality is at least somewhat contingent.
A theist might assert that moral principles are whatever God says they are and they as eternal and unchanging as God himself. In theory that’s possible but in practice it never happens that way.
My own former tradition of evangelical Christianity is a case in point. Although we believed that the Bible was God’s Unchanging Word, we found ourselves in the uncomfortable position of having to explain away supposedly eternal commands ranging from keeping the sabbath to women not being allowed to teach men. I suspect other traditions whose morality is based on what God has literally written in stone face similar conundrums. If the moral code is eternal, then we have not yet seen it on Earth.
This is not to say that morality is arbitrary. Far from it. Just as there are physical characteristics of humans that distinguish us from other species, there are moral characteristics that seem to suit us best. For example, take monogamy. That ideal has had a salutary effect on our social development, giving almost every woman a reliable support for her children and almost every man a reason to be productive. However, it would be entirely unsuitable for bees, whose social organization is exquisitely optimized around a single bearing female.
Moral norms evolved one way for bees, and another way for us. As human society continues to evolve, what makes us flourish may change, too. That’s what I think morality is: whatever best makes us flourish.
An open-minded observer cannot help but notice that moral principles are memes that continually battle each other for control of our minds. Over time, the memes that gain the upper hand are those that make their hosts (that’s us) flourish.
Maslow’s famous Hierarchy of Needs put physiological survival at the base and morality at the top. Our first need as a species, and the first to be fulfilled, was survival. As we became more firmly rooted in our niche, we were able to progress up the Hierarchy, until in the 21st century most of us in the First World think all day about the top level — self-actualization — and barely give survival a thought.
In the same way, primitive moral systems emphasized tribal cohesion and survival. It was just fine to enslave or wipe out rival tribes, stone heretics and so on. Now, thanks to prosperity, commerce, and other factors, we are past that. Our moral systems are based on universal rights rather than tribal exceptionalism; on freedom of thought rather than conformity; on mutual respect rather than authority.
Economic progress can give us the luxury of more enlightened morals, and better morals in turn promote prosperity and happiness.
It is said that morality is a straight and narrow path. That may be true, but it is not level. It rises with our progression as a species.