I wish to begin by commending Stephen's initial chapter for its insights and elegance. We agree on many points, including the view that true immortality (with no exit) would not be worthy of choice by human beings. We both take seriously the various challenges to the potential desirability of radical life extension under favorable circumstances (although we come to different conclusions about them). Additionally, I agree with Stephen about the fact that environmental concerns pose significant challenges for the desirability of immortality—challenges an optimist needs to address. We do however disagree about my contention that radical life extension under favorable conditions could be worthy of choice. Perhaps it is understandable that in a debate book, I’ll focus on points of disagreement in what follows.