Four lengthy essays — by primatologists Jessica Flack and Frans de Waal, cultural anthropologist Christopher Boehm, philosopher Elliot Sober and evolutionary biologist David Sloan Wilson, and philosopher Brian Skyrms — plus no fewer than 43 short commentaries, all revolving around the evolutionary origins of morality. Noam Chomsky comments, "Thoughtful and informative, (the essays) provide a good basis for appreciating what has been achieved, and what the prospects might be, in a domain of inquiry that is of fundamental importance for understanding our essential nature."