There is an Inca incantation which stated said roughly: Lord, give me spiritual peace so that I can acquiesce to what I cannot change, give me courage so that I can change what I can change, and give me wisdom so that I can distinguish one from the other. Obviously, this incantation can be regularly repeated by any gerontologist, since it is very difficult to distinguish aging from the processes which enhance the organism's viability, aging from diseases, and the mechanisms of aging in various species of animals. According to N. Shock, who compiled a valuable bibliography of the works on...