Atheists can refuse to believe any assertion of morality made by atheists by exactly the same means they use to refuse to believe in God "prove it", "why should I," "so what," which all boils down to the crux of your dilemma if you want to create those atheist substitutes for the real thing, "Who's going to make me?"
Tell me how any atheist substitute for religious morality wouldn't be vulnerable to rejection on the basis of that atheist question, "Who's going to make me?"
In Sartre's famous essay, he connected morality to common humanity; essentially a version of the Golden Rule.
ReplyDeleteExcept he cast it rather negatively: he argued that in choosing how to live, you choose for all humankind. In choosing what you think people are (atheist, religious, generous, selfish, cruel, kind), which is to say, how you treat people and expect them to behave, you choose for all humanity. He saw it as a terrible burden, but, being an atheist, a necessary one.
He also didn't spend his time rejecting God: he just took the absence of God as a given, and got on with it. Quite unlike the New Atheists and their on-line followers.