The problem of senescence, as reflected in the history of reli- gion and philosophy, has long been one of the greatest concerns of humankind. In contrast, gerontology as a branch of science is still comparatively young. During the past decade, concomitant with rapid progress in our understanding of the basic life sciences, vast stores of knowledge about biological aging have been accumulated. This knowledge, however, arising from many scientific disciplines and focused on varying levels of biologic organization, seems almost random and covers everything from molecules to human societies....