Geriatricians have long distinguished aging from disease. Yet the separation of these two processes and these in turn from the effects of the environment is most difficult. Therefore, as the possibility of manipulating the aging process is considered, what the elder of tomorrow will look like can only be speculated about. Might it be possible to alter the effect of aging on one organ system and not others? Should we be stating that disease appears a certain number of years before the end of life rather than noting its onset from the moment of birth? If the phenomenon of aging can be manipulated, the distinction between aging and disease may become increasingly difficult except for conditions clearly caused by an infectious agent or an environmental toxin.