This is not simply that nihilism is morally repulsive (though it is), it is that it is grounded in ignoring some obvious facts about life–the same sort of facts which are ignored by materialism.
As is often the case, Alex Rosenberg makes an excellent example:
In a world where physics fixes all the facts, it’s hard to see how there could be room for moral facts. In a universe headed for its own heat death, there is no cosmic value to human life, your own or anyone else’s. (Atheist’s Guide to Reality, pp. 94-95)
To those in thrall to the long-discredited verification principle (that is “we shouldn’t believe anything without physical evidence”), nihilism is simply the logical end point. Utter meaninglessness is the foregone conclusion when one rejects from the outset any part of reality that could possibly reveal meaning.
But most materialists, trying to soften the blow of so dark a proclamation, tend to play up “subjective meaning”, or something of the sort. In fact, Rosenberg does so himself:
The bad news first: We need to face the fact that nihilism is true. But there is good news here, too, and it’s probably good enough to swamp most of the bad news about nihilism. The good news is that almost all of us, no matter what our scientific, scientistic, or theological beliefs, are committed to the same basic morality and values. (ibid, p. 95)
It doesn’t matter, so the argument goes, that there is no objective morality, because even people who think this will behave as if there were such a thing. Rosenberg calls this “nice nihilism”.
But I’m not convinced that a cute nickname deals with the real issues. Certainly, it doesn’t deal with the existential dread so many face, and that thinkers like Rosenberg simply wave off. But I’m not about to argue personal reactions; I doubt that there is a way to convince a complacent nihilist that others genuinely find his position deeply unconscionable.
Rather, I’d like to draw attention to the blatant irrationality of all this. Rosenberg points out that all people will try to be “good”, regardless of whether or not they believe there really is such a thing as good. While this is true, one suspects that something has been missed.
After all, what is this statement but the direct claim that materialists are consistently irrational in their daily lives?
Nearly every materialist I’ve encountered has demanded that beliefs be based on evidence. That is, I hear the demand until we begin speaking on moral issues, in which case believing anything that strikes one’s fancy is generally held to be permissible.
The logical issues with this approach to morality are legion, but let us set them aside. For, under them all, there is the fact that these individuals, after insisting that evidence is the only legitimate ground for belief, are willing to completely abandon the concept when it comes to a massive area in the living of life.
This is not simple hypocrisy. This is the best example of the fact that this position is simply unlivable–even for its most fervent supporters. It is the utter failure of this philosophy to address the real issues of life.
Thus, it is one more piece of evidence that materialism is simply denying the existence of what it cannot explain, rather than expanding its view in order to explain it.