Worse, the worldview of science is rather chilling. Not only do we not find any point to life laid out for us in nature, no objective basis for our moral principles, no correspondence between what we think is the moral law and the laws of nature, of the sort imagined by philosophers from Anaximander and Plato to Emerson. We even learn that the emotions that we most treasure, our love for our wives and husbands and children, are made possible by chemical processes in our brains that are what they are as a result of natural selection acting on chance mutations over millions of years. And yet we must not sink into nihilism or stifle our emotions. At our best we live on a knife-edge, between wishful thinking on one hand and, on the other, despair.
I would really like to hear the author, on rational grounds, try to defend his choice of the word "must" in the penultimate sentence of this paragraph. In a consistently naturalistic world, all human "musts" and "shoulds" are as meaningless as belief in God.
And, I would add, it isn't just emotions that are the mere effect of chemical processes and chance mutations. The same MUST be said for so-called "rational" thought (such as scientific theorizing) itself.