(my own term) That is the reductionistic view, and the dominant view of our time, academically speaking. And many people follow it without really thinking about it–it is as transparent to us as the air that we breathe. But let’s define it:
It is this: Whatever you do is some form of stimulus-response. Just as a hammer is not intrinsically “bad” for missing the nail, there is no human morality, either. Just like the hammer, whatever YOU do is merely metaphysically necessary–you are just more complex than a hammer (well, some of you ). So there can be no right or wrong–only fully environmentally determined preferences and innate reflexes.
Sure, you have the sense that you chose, but that is an illusion–you no more chose than did that hammer when it hit the nail. You simply do not exist as a moral agent. You did not choose to love your spouse, you just are necessarily responding. You are merely a sack of meat, and you react to input in just the way a sack of meat necessarily does.
You are a man on the beach, under a hot sun (Albert Camus, The Stranger). We can talk about Camus’ effort to redeem that line of thought (The Myth of Sisyphus), but that effort totally does not work. So Camus hides that fact (as do all those philosophers, like Foucauld and Derrida) by taking logical refuge in “absurdity” or sheer incomprehensibility (“The fact that what I say is not meaningful to you is in itself meaningful”).
But many even today claim that very same enlightenment-through-ignorance so they don’t have to defend their positions (see: “Democrats“)
At heart is a moral-agency-denying biological reductionism. THAT is also the (often unspoken) basis for ALL Post-Modern approaches. Biological reductionism and Post-Modern thought are just two sides of the same coin. BOTH deny Truth and moral agency.
And neither one buys much…
But it’s hard, if not logically impossible, to buy moral agency and NOT have some species of Theism. THAT is why Post-Modernism and Scientism deny agency.