Atheism is intrinsically linked to nihilism. Atheists will deny this. But it doesn’t change anything. However, now and then, some atheist thinker will come along and acknowledge this truth. Someone like the philosopher of science Alex Rosenberg. Below the fold are some excerpts from his essay.
Darwinism thus puts the capstone on a process which since Newton’s time has driven teleology to the explanatory sidelines. In short it has made Darwinians into metaphysical Nihilists denying that there is any meaning or purpose to the universe, its contents and its cosmic history. But in making Darwinians into metaphysical nihilists, the solvent algorithm should have made them into ethical nihilists too. For intrinsic values and obligations make sense only against the background of purposes, goals, and ends which are not merely instrumental. But the leading Darwinian philosophers have shied away from this implication and instead have embraced ethical naturalism. And this despite the ever-increasing power of Darwinism to explain away normative ethics as a local adaptation.
Nihilism consists in the following claims: a) normative terms–good, bad, right, duty, etc–do not name real properties of events or things, either natural nor non-natural ones; b) all claims about what is good in itself, or about categorical moral rights or duties, are either false or meaningless; c) the almost universal beliefs that there are such properties and that such claims are true can be “explained away” by appropriate scientific theory. Nihilism takes the form of what J. L. Mackie  calls an “error theory.” It does not deny that beliefs about norms and values can motivate people’s actions. It does not deny the felt “internalism” of moral claims, nor does it deny that normative beliefs confer benefits on the people who hold them. Indeed nihilism is consistent with the claim that such beliefs are necessary for human survival, welfare and flourishing. Nihilism only claims that these beliefs, where they exist, are false. It treats morality as instrumentally useful —instrumentally useful for our nonmoral ends or perhaps the nonmoral ends of some other biological systems, such as our genes for example. As such, it must undermine the values we cherish. If Darwinism underwrites Nihilism, Dennett cannot be right about Darwinism’s salubrious effects for “the meanings of life”. However Nihilism can be, as one might say, “nice”, provided that in its explaining away of ethics, it also shows that we are in fact disposed to behave nicely–-to cooperate, be altruistic, show guilt and shame, anger and resentment in just the way we would if some morality were true, right, or real. Darwinian Nihilism is the thesis that the theory of natural selection and its application to biological data explains why morality is at most an instrumentally useful illusion. According to the Darwinian Nihilist, the theory of natural selection can both show that we are in error about the status of moral claims, and, perhaps more importantly, can explain this why the error is so widespread.
Darwinian Nihilism explains away ethics by showing that our ethical beliefs reflect dispositions very strongly selected for over long periods, which began well before the emergence of hominids, or indeed perhaps primates (vide the vampire bat). These dispositions are so “deep” that for most people most of the time, it is impossible to override them, even when it is in our individual self-interest to do so, still less when there is no self-interested reason to do so. Hence, the Darwinian Nihilist expects that most people are conventionally moral, and that even the widespread acceptance of the truth of Darwinian Nihilism would have little or no effect on this expectation. Most of us just couldn’t persistently be mean, even if we tried. And we have no reason to try.