Regenerative medicine is rich with promethean promises. The use of human embryonic stem cells in research is justified by its advocates in terms of promises to cure a wide range of diseases and disabilities, from Alzheimer s and Parkinsonism to the results of heart attacks and spinal cord injuries. More broadly, there is the promethean allure of being able to redesign human biological nature in terms of the goals and concerns of humans. Needless to say, these allures and promises have provoked a wide range of not just moral but metaphysical reflections that reveal and reflect deep...