What if you found out you could live a healthy life lasting for a thousand years or longer? Advances in biomedical technology raise the theoretical possibility that people could dramatically prolong or even indefinitely extend "healthy" human life. If this science of "radical life extension" is realized and the technology becomes widely available, it would arguably have a more radical impact on humanity than any other development in history. This book is the first concerted effort to explore the implications of radical life extension from the perspective of the world's major religious traditions.