Abstract

Part I (Skepticism) contains analyses of the basic varieties of ethical skepticism and culminates in the idea that the refutation of ethical skepticism--or, what is the same thing, the discovery of the rational basis of morality--consists of a proof of the factual thesis that there exists in human beings a common underivative moral self that consists of an innate normative-practical source (or principle-spring) of human moral judgment and behavior. Part 2 (The Basis of Morality) develops the methodology for establishing this factual thesis and develops as well an argument employing this methodology that actually establishes it. This argument is to the effect that nature through the process of evolution-by-natural-selection built into us humans the following principle as the rational basis of morality: We ought to act only in those ways whose universal performance is both possible and consistent with the rational self-interest of every member of our species.