What is radical enhancement? -- Radical enhancement and posthumanity -- The technologist : Ray Kurzweil and the law of accelerating returns -- Is uploading ourselves into machines a good bet? -- The therapist : Aubrey de Grey's strategies for engineered negligible senescence -- Who wants to live forever? -- The philosopher : Nick Bostrom on the morality of enhancement -- The sociologist : James Hughes and the many paths of moral enhancement -- A species-relativist conclusion about radical enhancement.