Taking its title from lines in T.S. Eliot's Four Quartets - "Go, go, go, said the bird: human kind cannot bear very much reality" - this book sets out to expose some of the realities which, at this stage of our evolution, human beings cannot bear to accept. Successive chapters examine rationality, conscience, religion, perception, sexuality, free will, moral responsibility and crime, pointing out the incomprehension which mars our approach to each topic. One of the book's themes is that we are still, below the surface, a savage species, clinging to our misconceptions because they liberate and justify our cruelty to one another.

Despite its deadly serious and controversial approach, the book is enlivened by humour, personal stories, quotes from others and bits of poetry. It is not academic but readily accessible to the general reader. In the last chapter, the author sums up by saying that, although the human species now is what it is, some of us can imagine a better one: "A species that isn't irrational, ignorant, credulous, uncomprehending, self-defeating, ill at ease with its sexuality, mired in contradictory beliefs, impelled by a savagery let loose by misperception and misunderstanding", and asks: "Could this imaginary species ever become a real one?".