The March 2002 symposium Human Dignity and Reproductive Technology brought together philosophers, theologians, scientists, lawyers, and scholars from across the United States. The essays of this book are the contributions of the symposium's participants.

We agree that supernatural beliefs are pervasive. However, we propose a more general account rooted in how people trace ordinary objects over time. Tracking identity involves attending to the causal history of an object, a process that may implicate hidden mechanisms. We discuss experiments in which participants exhibit the same “supernatural” beliefs when reasoning about the fates of cups and automobiles as those exhibited by Bering's participants when reasoning about spirits.