Gray knows what Nietzsche knew but the likes of Harris, for some reason, cannot fathom; viz., that you can't derive "ought" from "is." Gray writes:
"It’s probably just as well that the current generation of atheists seems to know so little of the longer history of atheist movements. When they assert that science can bridge fact and value, they overlook the many incompatible value-systems that have been defended in this way. There is no more reason to think science can determine human values today than there was at the time of Haeckel or Huxley. None of the divergent values that atheists have from time to time promoted has any essential connection with atheism, or with science. How could any increase in scientific knowledge validate values such as human equality and personal autonomy? The source of these values is not science. In fact, as the most widely-read atheist thinker of all time argued, these quintessential liberal values have their origins in monotheism."
And just who might that atheist thinker be? It's none other than Nietzsche, who understood atheism while remaining largely misunderstood even today. Gray writes: "The reason Nietzsche has been excluded from the mainstream of contemporary atheist thinking is that he exposed the problem atheism has with morality." Nietzsche, Gray, and the likes of Georges Bataille understood that "when monotheism has been left behind morality can’t go on as before. Among other things, the universal claims of liberal morality become highly questionable."
This is because (now pay attention to this) "Nietzsche was clear that the chief sources of liberalism were in Jewish and Christian theism: that is why he was so bitterly hostile to these religions. He was an atheist in large part because he rejected liberal values."
Can a liberal morality be embraced without God? Not at all. "The trouble is that it’s hard to make any sense of the idea of a universal morality without invoking an understanding of what it is to be human that has been borrowed from theism. The belief that the human species is a moral agent struggling to realise its inherent possibilities – the narrative of redemption that sustains secular humanists everywhere – is a hollowed-out version of a theistic myth. The idea that the human species is striving to achieve any purpose or goal – a universal state of freedom or justice, say – presupposes a pre-Darwinian, teleological way of thinking that has no place in science."
Now that is some beautiful reasoning. Anyone who wants to overcome the abyss of relativism (and nihilism) and have "their values secured by something beyond the capricious human world had better join an old-fashioned religion." Indeed.
Gray has a lot more to say, and says it well.