Acknowledgements. 1. Introduction; L.S. Parker, R.A. Ankeny. Part One: Historical Reflections on Core Concepts. 2. The Classical Gene: Its Nature and Its Legacy; G.E. Allen. 3. Dissolving Dominance; D. Allchin. 4. Flies, Genes, and Brains: Oskar Vogt, Nicolai Timoféeff-Resovsky, and the Origin of the Concepts of Penetrance and Expressivity; M.D. Laubichler, S. Sarkar. 5. From Reproductive Responsibility to Reproductive Autonomy; D. Paul. Part Two: Perspectives from the Philosophy of Science. 6. Understanding Genetic Causation and Its Implications for Ethical Issues Concerning Medical Genetics; F. Gifford. 7. Reduction Reconceptualized: Cystic Fibrosis as a Paradigm Case for Molecular Medicine; R.A. Ankeny. 8. Scylla and Charibdis: Adaptationism, Reductionism, and the Fallacy of Equating Race with Disease; J.L. Graves Jr. 9. Behavior as Affliction: Common Frameworks of Behavior Genetics and Its Rivals; H.E. Longino. Part Three: Explorations of Ethical, Social, and Legal Consequences. 10. The Morality of Prenatal Testing and Selective Abortion: Clarifying the Expressivist Objection; L. Carlson. 11. Meliorism at the Millennium: Positive Molecular Eugenics and the Promise of Progress without Excess; A. Silvers. 12. Personal Identity and the Moral Appraisal of Prenatal Therapy; D. Wasserman. 13. Conceptual and Moral Problems of Genetic and Non-Genetic Preventive Interventions; 14. Unraveling the Codes: The Dialectic between Knowledge of the Moral Person and Knowledge of the Genetic Person in Criminal Law; J.H. Robinson, R.M.Berry. Notes on Contributors. Index.