Abstract The structural-systematic philosophy requires a moral theory. This essay seeks to determine whether either of two recent works, Joshua Greene’s Moral Tribes and Michael Tomasello’s A Natural History of Human Morality, should influence that theory. It first argues that Greene’s fails to make its case for utilitarianism over deontology. It then argues that Tomasello’s thesis that early humans developed moralities of sympathy and fairness, particularly when taken in conjunction with aspects of Alan Gewirth’s moral theory, fits well with the moral theory envisaged by extant works on the structural-systematic philosophy. The envisaged theory maintains the objectivity of human rights.