A nuanced discussion of human enhancement that argues for enhancement that does not significantly exceed what is currently possible for human beings.

Series Foreword ix Preface xi Acknowledgments xv 1 Radical Human Enhancement as a Transformative Change 1 Transformative Change and Invasion of the Body Snatchers 5 The Rational Irreversibility of Some Transformative Changes 10 Positive and Negative Transformative Changes 14 Radical Enhancement as a Negative Transformative Change 15 2 Two Ideals of Human Enhancement 17 Defining Human Enhancement 18 The Objective Ideal of Human Enhancement 20 The Instrumental and Intrinsic Value of Human Capacities 26 Anthropocentric Ways of Evaluating Enhancements 27 3 What Interest Do We Have in Superhuman Feats? 33 The Value of Enhanced Marathons 34 Simulation and Meaning 36 Is Human Enhancement the Right Way to Pursue External Goods? 44 Is the Distinction between Internalizing and Externalizing Enhancement Philosophically Principled? 50 4 The Threat to Human Identities from Too Much Enhancement 55 Two Psychological Accounts of Personal Identity 56 A Threat to Identity from Life Extension 57 Radical Enhancement and Autobiographical Memory 60 How Does Autobiographical Memory Work? 62 An Asymmetry in Our Attitudes toward Past and Future 66 The Tension between Enhancement and Survival 69 The Analogy with Childhood 70 Why Radical Enhancement Is More Psychologically Disruptive Than Growing Up 75 The Regress Problem: The Tragedy of Unending Enhancement 765 Should We Enhance Our Cognitive Powers to Better Understand the Universe and Our Place in It? 81 Understanding the Consequences of Cognitive Enhancement for Science 84 Two Ways in Which Human Science and Radically Enhanced Science Might Be Fundamentally Different 88 Differences in Idealization as Fundamental Differences between Human and Radically Enhanced Science 89 Idealizations That Enhance the Power of Scientific Explanations 93 Mathematics as a Bridge between Human and Radically Enhanced Science 95 Human Science, Radically Enhanced Science, and the Theory of Everything 97 Dawkins and Haldane versus Deutsch on the Limits of Human Science 98 How Different Idealizations Generate Different Theories of Everything 102 Valuing Human Science and Radically Enhanced Science 105 Radical Enhancement Reduces the Intrinsic Value of Our Cognitive Faculties 106 What of Scientific Enhancement’s Instrumental Benefits? 109 6 The Moral Case against Radical Life Extension 113 Two Kinds of Anti-Aging Research 114 The SENS Response to the Seven Deadly Things 117 Is Aging Really a Disease? 120 The Testing Problem 122 Why WILT (and Other SENS Therapies) Will Require Dangerous Human Trials 126 Where to Find Human Guinea Pigs for SENS 129 Will Volunteer Risk Pioneers Help Out? 131 Ethical Anti-Aging Experiments Not Now, but Some Day? 135 7 A Defense of Truly Human Enhancement 137 The Ubiquity of Human Enhancement 139 Enhancement and Heredity 142 Defining Genetic Enhancement 143 The Interactionist View of Development 144 Six Ways in Which Genetic Enhancements Could Turn Out to Be More Morally Problematic Than Environmental Enhancements (but, in Fact, Do Not) 146 The Ideal of Truly Human Enhancement 154 8 Why Radical Cognitive Enhancement Will (Probably) Enhance Moral Status 157 Enhancing Moral Status versus Enhancing Moral Dispositions 158 Why It’s So Difficult to Enhance the Moral Status of Persons 159 A Justification for (Talking about) Moral Statuses 160 Three Obstacles to Moral Enhancement 161 (1) The Problem of the Logic of Thresholds 161 (2) The Problem of How to Improve upon Inviolability 163 (3) The Problem of Expressing Moral Statuses Higher Than Personhood 164 Three Attempts to Describe Higher Moral Statuses 165 DeGrazia’s Dispositionally Superior Post-Persons 167 McMahan’s Freer, More Conscious Post-Persons 169 Douglas’s Enhanced Cooperators 173 Criteria for Higher Moral Statuses and the Expressibility Problem 174 Why Cognitively Enhanced Beings Are Probably Better Than Us at Judging Relative Moral Status 176 Why Sufficiently Cognitively Enhanced Beings Will (Probably) Find That Cognitive Differences between Them and Us Mark a Difference in Moral Status 177 Two Hypotheses about Higher Moral Statuses 178 9 Why Moral Status Enhancement Is a Morally Bad Thing 181 Some Assumptions 182 Why a Change in Relative Moral Status Is Likely to Lead to Significant Harms for Human Mere Persons 184 Why Post-Persons Will Probably Identify Many Supreme Opportunities Requiring the Sacrifice of Mere Persons 189 What Complaint Can Mere Persons Make about the Harms They Suffer in Mixed Societies? 190Why a Loss of Relative Status Is Unlikely to Be Adequately Compensated 193 10 A Technological Yet Truly Human Future—as Depicted in Star Trek 195 Notes 201 Index 213