In his introduction to the logic of morals Karl Menger (Vienna) maintains that only two kinds of ethical inquiry are fruitful—the psychology or biology of morals and the logic of morals. The first of these is an empirical science which discovers what value judgments have actually been made and correlates them with various other factors. In this way it provides material for the logic of morals, which neither discovers empirical facts nor analyses them, but simply points out logical relations. In this book Menger discusses the nature of ethical judgments and carries out some investigations of the logical type.