That is the new Roger Scruton book, which I finished with pleasure. Here is one good passage:
Optimism…is the other side of a kind of existential despair, a longing to retreat from the complexities of the great society to the primordial simplicity of the undifferentiated tribe. It expresses a kind of distrust of humanity, an inability to allow that we can actually move on from our original nature, and create a flexible, reasonable and charitable "we," which is not a collective "I" at all, but the by-product of individual freedom. But this distrust is unfounded. The world is, in fact, a much better place than the optimists allow: and that is why pessimism is needed.