by Leon R. Kass

About the author: A physician and biochemist, Leon R. Kass is the Addie Clark Harding Professor in the Committee on Social Thought and the College of the University of Chicago. He is the coauthor of The Ethics of Human Cloning and the author of Toward a More Natural Science: Biology and Human Affairs.

Editor’s Note: The following viewpoint was originally presented as testimony before the National Bioethics Advisory Commission, which was directed by President Bill Clinton to review the implications of cloning humans. In June 1997, the commission recommended that research into human cloning be banned for three to five years.

Iam deeply grateful for the opportunity to present some of my thoughts about the ethics of human cloning, by which I mean precisely the production of cloned human beings.

This topic has occupied me off...