In this intriguing volume, futurist and author Michael G. Zey imagines a time in which technology has stretched human life spans to four hundred years or more. Genetic engineering, cloning, and stem-cell technology will eradicate diseases and allow for nanoscopic repair and maintenance of the body. "Smart drugs" and caloric restriction programs will largely stop aging and ensure healthy bodies and sharp minds indefinitely.

Grounding his speculation in contemporary scientific research, Zey's optimistic vision sees retirement replaced by hiatuses between careers, and leisure time spent...