"You would not get out of your chair and walk across the room, if Nature had not her bag of illusions."
Under atheist metaphysics, there was no Creator, Designer, or even pantheistic personality such as Mother Nature to give the universe any kind of overarching purpose, design, direction, intent, or outcome.
Is there anything under atheist metaphysics that could have designed or directed the universe—any universe, its properties, its very existence—one way and not another?
If no, is there anything making said universe more than a matter of blind, random, mindless, purposeless chance?
If no, in such a universe, can there be anything of intrinsic value?
If no, then what are the moral and meaningful experiences, feelings, ideas, and habits fashioned in humans through natural selection about?
"Now, it is worthy of remark that [Thomism] is the only working philosophy. Of nearly all other philosophies it is strictly true that their followers work in spite of them, or do not work at all. No sceptics work sceptically; no fatalists work fatalistically; all without exception work on the principle that it is possible to assume what it is not possible to believe. No materialist who thinks his mind was made up for him, by mud and blood and heredity, has any hesitation in making up his mind. No sceptic who believes that truth is subjective has any hesitation about treating it as objective."
—G.K. Chesterton, Saint Thomas Aquinas: The Dumb Ox