Dawkins explores the relationship between morality and religion, questioning whether belief in God is necessary for humans to be good. Dawkins begins by addressing the common belief among religious people that without religion, morality would not exist or would lose its foundation.

Dawkins receives many letters, some expressing extreme hostility from religious individuals who see him as an enemy of faith. These letters often display a moral outrage that is ostensibly rooted in religious belief, yet are filled with hatred and threats, highlighting a contradiction in the moral behavior of these individuals.

The chapter delves into the Darwinian origins of moral sense, challenging the notion that natural selection, which emphasizes survival of the fittest, cannot explain altruism and moral behavior. Dawkins introduces the concept of the “selfish gene,” explaining that genes ensure their own survival by sometimes promoting altruistic behavior. This is because altruism towards kin and reciprocal altruism can increase the chances of a gene being passed on.

Dawkins identifies four main Darwinian explanations for altruistic behavior: kin selection (helping relatives), reciprocal altruism (mutual aid), building a reputation for generosity, and Zahavi’s handicap principle, where acts of generosity are signals of fitness or superiority.