Robert Buckman is an MD and card-carrying humanist who wants us to know that we don’t have to believe in order to behave. Belief in an external god who has set out prescribed rules of conduct can be, he argues, counter-productive to ethical behaviour. For example, in an intriguing section on current knowledge about the brain’s right temporal lobe, Buckman suggests that humans are hard-wired for war, and that organized religion exacerbates this tendency. His alternative – and a strategy, if he’s right, for lessening our natural aggression – is a set of rules based on our psychology and our biology. These would engage the way we are, as opposed to the way a god ordained us to be.

The author’s tone is conversational and clear, and he bends over backward to try to conduct his argument outside of considerations about the existence or non-existence of a deity. Still, the intended audience for this book is made up of those who believe in a parental god “out there,” and who govern their behaviour in terms of rules backed up by threats of hellfire and promises of heaven.

Buckman divides believers into those who look within for moral guidance and those who look without. But surely most believers consult an inner sense of god as well as external traditions? Perhaps the real audience for this book is humanists and others who enjoy arguing against a fire-and-brimstone view of the universe – though some would argue that view now has few adherents.

Although Buckman’s arguments are clear, they are for the most part not fresh, and the opening section is so careful not to offend that it ends up being bland. He is also weak on showing why humanism itself should not be seen as a system based on faith.