Ayala (American philosopher and biologist) has presented new theories on the evolutionary ethical explanations. Due to the large scope of Ayala’s discussion on evolutionary ethics, only some of his theories will be reviewed in this paper after mentioning Ayala’s theoretical foundations about the formation of moral sense and moral norms. Following Darwin, Ayala distinguishes the moral sense and the moral norms accepted by the human community. Therefore, he believes that the biological-natural processes lead to the evolution of the human mind; this growth and development in the mind results in the moral sense in the human. On the one hand, the norms and ethical systems of any human society have been emerged due to the cultural evolution in that country. Hence, cultural evolution is the foundation of Ayala’s ethical pluralism theory. As such, Ayala advocates the objectivity of moral values and Kantian subjective morality. He rejects the dependence of the moral sense on evolutionary mechanisms such as group selection and relative selection since he, like Kant, regards human rationality as the only reason for justifying moral sense. In this paper, Ayala’s theories on ethical pluralism and the role of cultural evolution in the formation of moral norms are discussed and criticized. Ayala’s success in establishing a universal normative ethical system will be approached skeptically; however, his biological explanation of the origin of moral sense can be considered as a Kantian account of morality.
