Biogerontology, or biological aging research, has succeeded in manipulating the aging process of laboratory organisms. Biogerontological researchers believe that these findings can also be applied to humans. An ethical reflection should take place promptly to prevent research successes from leading future developments in an undesirable direction. The context for this reflection lies in demographic change and altered perceptions of aging. On one hand, there are hopes that successful new interventions in aging processes could mitigate or even completely prevent the negative consequences of demographic change. On the other hand, interventions in aging processes could also raise ethical issues. This book initially presents biogerontological theories, concepts, and methods briefly and systematically examines the subsequent implications.