Reason and Human Ethics argues that a secular, biological, teleological basis of human ethics exists and that reasoning and critical thinking about both ends and means are essential to human ethics. It examines how these principles apply in the contexts of individual ethics, social ethics, citizen ethics, media ethics, and political ethics.

Chapter 1 ("What Is the Basis of Human Ethics?") discusses the various theories of the basis of ethics over the millennia. It concludes that ethics is properly founded on a secular, biological, teleological understanding of human nature.

Chapter 2 ("Human Reason") begins with a discussion of how reason relates to secular teleology. It argues that reason is-contrary to much of modern philosophy and science-properly directed to human ends as well as means. It explains the differences between abstract and practical reasoning and between formal and informal logic. Unlike mathematics and physics, ethics involves practical reasoning and informal, nonsymbolic logic. The chapter concludes with an extended discussion of common fallacies and the importance of critical thinking.

Chapter 3 ("Individual Ethics") addresses the appropriate ethical orientation toward ourselves as individuals. It explains why we should want to be rational, how human reason is related to cerebral maturation, the life of reason, and general departures from a rational life. It concludes with a discussion of the ethical mean of Confucius and Aristotle and how that mean properly applies to such moral virtues as courage and moderation.

Chapter 4 ("Social Ethics") considers how individuals should think and act regarding other human and nonhuman beings. This chapter discusses when we should or should not express ethical judgments about others, the merits and limitations of the Golden Rule, prejudice and discrimination, veracity, friendship, romantic relationships, family, work, business ethics, environmental ethics, the ethical treatment of nonhuman animals, and issues regarding force and fraud.

Chapter 5 ("Citizen and Media Ethics") discusses, among other things, the long-forgotten concept of public virtue, the ethical imperative of reason in public discourse and conduct, ideologies of the far Right and far Left, and media ethics.

Chapter 6 ("Political Ethics") is about the ethics of political leadership. The first major section is on authoritarian, tyrannical, and totalitarian political leaders, with a discussion of Plato's account of oligarchical and tyrannical rulers in his Republic and Seventh Letter and the examples of Joseph Stalin, Adolph Hitler, and Vladimir Putin. The second section addresses irrational democratic-republican political leadership, with examples being the self-acknowledged "gut instinct" leadership styles of U.S. presidents George W. Bush and Donald J. Trump and the latter's advanced flirtation with authoritarian ideology and practice. The concluding section is about rational democratic-republican political leadership: what it would be and a possible example in President John F. Kennedy's leadership during the 1962 Cuban Missile Crisis.

An epilogue sums it all up, and the appendix discusses the theological and violent conflicts among the claims to revelation.