There are three possible sources of morality: faith; reason; authority. These usually take the form of: religion; philosophy; society or someone claiming to speak for it. The three can get mixed up; indeed, the morality of most eras societies and individuals contain elements of all three. But one of the three is usually dominant - faith/religion had its heyday in medieval Christendom; reason/philosophy in classical Greece; authority/society in twentieth century communism.
Few atheists have a reasoned philosophic base to their ethics. Most simply co-opt the moral precepts established by the authority invoked by Moses and the faith invoked by Jesus, then claim that you don’t need religious faith to follow the essence of those precepts. Nineteenth century philosophers such as Auguste Compte and Karl Marx took that approach, as do modern atheists such as Dawkins and sundry Leftists.
Unfortunately mainstream philosophy has disintegrated into ethical dead ends. Pragmatism tells us to act to achieve values but not how to choose which values. Existentialism tells us to do anything to authenticate the angst. Postmodernism tells us to tear everything down so another narrative can have a go. Greens tell us we infest the earth and if we won’t die the least we can do is make our footprints as few and small as possible. So it shouldn’t surprise anyone when youth turn away from morality as such - or towards a medieval source for moral direction.
But medieval faith is an abominable source of morality. Faith requires the suspension of our human means of survival – reason. And for a human to try and live by suspending reason is like a bird trying to live by suspending flight or an ant by suspending instinct or a plant by suspending photosynthesis. But isn’t Christianity the source of the West’s success? No - Christian faith dominated the West during the Dark Ages, it was after the Greek culture and reason was rediscovered that the West produced the Renaissance, the Enlightenment, rights, science, industry, and modernity. So where do we go from here?
Our task, I submit, is to discover a rational ethical system. Morality is not a matter of doing God’s bidding, because it’s God’s bidding; or one’s duty, because it’s ones duty; or what’s unselfish, because it’s unselfish. We are allowed to ask: why should we pursue this or that moral value? And, shock horror, what’s in it for me? That’s the sort of question the Greeks asked their philosophers. That’s what men started asking during the Enlightenment; until Imanual Kant booby traped their quest. But in the 20th century there was a philosopher who answered such questions. Her name was Ayn Rand. In a sentence her answers were: because this and that are required for reason to operate, and reason is your means of living on earth. So what’s in it for you is life.