This chapter advances the core argument of the book on the objectivity of a claim about the general human capacity for moral personality. In addition, it indicates the main characteristics of moral realism and a developed political theory. In today's philosophical debates, moral realism is an extension of scientific realism. Broadly speaking, the latter responds positively to the question “Does scientific inquiry give us knowledge of facts about unobservable entities?” As Chapter 3 will emphasize, it advances the claim that across theory changes, the basic terms of mature scientific theories refer to and capture more deeply features of the world. Moral realism responds positively to the question “Does our ethical inquiry give us knowledge of facts about human well-being?” This chapter concentrates on the basic ideas of a common good among free humans and ethical discovery. The first two sections sketch the main argument and suggest its significance; the last six offer a more worked-out version.

Some leading features of moral realism

In theoretical terms, Aristotle delineated the first, limited achievements of human freedom, manifested in the Greek city, and identified the justice of defensive wars. Yet he also legitimized that city's slaveholding; he contended that a large number of humans – so-called natural slaves – had no higher destiny than to furnish the material underpinnings of the citizens' good life.