My first inclination is to entitle this book [philosophical anthro- pology]—which will in any case be its library classification. But I hesitate to do this, since the term [philosophical anthropology,] is now used in a specialized sense. It has become largely synonymous with a group of philosophical efforts placed under the umbrella designation, [existential phenomenology]—works by Husserl, Heidegger, Merleau-Ponty, Buber, Sartre, and others. These works, quite different from one another in approach, do have some features in common. In the midst of the spread of totalitarian ide- ologies in the twentieth century, they responded by focusing on individual existence in the world as the starting point and the cen- tral issue for philosophical analysis. The keynote of such efforts has been the emphasis on introspective experience, and reliance on pure phenomenological analysis as a self-sufficient methodology. In existentialism and phenomenology, one finds occasional refer- ences to scientific developments—such as references by Sartre to Freudian psychology, or the general discussions of modern tech- nology by Heidegger—but no major efforts to incorporate con- temporary scientific data on human nature in any systematic way.
In twentieth-century Scholastic philosophy, based largely on the work of St. Thomas Aquinas (1225–1274), the branch of phi- losophy called [philosophical psychology] offered a different and somewhat systematic approach to questions about human nature. Metaphysical issues regarding human nature were considered—the relation of essence to existence in humans, the differentiation of