ABSTRACT
The more easily recognized symptoms of aging have often been described and some of these descriptions, such as Cicero’s, have become classic. The correct interpretation, however, of such phenomena and the estimate of the various biological mechanisms called into play during the later periods of life, are now counted as among the most important problems of modern biology. A fairly complete philosophy of life, based upon biologic principles, should aid greatly our understanding of the behavior of old people, our appreciation of the source of their motives, and comprehension of their symbols of speech.
