This book is a bold mapping out of areas of research that should be explored in detail by the medical and social sciences during coming decades. It is based on the belief that the extraordinary medical progress of the first half of this century, which proceeded largely from the laboratory and clinic, can be continued only if the medical sciences embrace the bio-social field of research. Originally published in 1954. A UNC Press Enduring Edition -- UNC Press Enduring Editions use the latest in digital technology to make available again books from our distinguished backlist that were previously out of print. These editions are published unaltered from the original, and are presented in affordable paperback formats, bringing readers both historical and cultural value.