Kass, 63, has been engaged in bioethics for more than 30 years. A professor at the University of Chicago on a two-year leave and a Fellow at the American Enterprise Institute, a conservative Washington think tank, he is considered something of a Renaissance man. And both his scholarship and professorial skills will be called upon as he leads the bioethics council -- established to advise Bush on contentious issues like cloning and stem cell research.
The council is an advisory, not a regulatory, body. Kass said its goal is "not to come to a consensus," but to provide Bush with the different views of council members on cloning and other issues.
Legislation on cloning is now before Congress. A bill sponsored by Sen. Sam Brownback, R-Kan., would ban both cloning for human reproduction and cloning for biomedical research, known as "therapeutic" cloning. Legislation sponsored by Sen. Diane Feinstein, D-Calif., would ban only reproductive cloning.
He is the author of several books, including, with James Q. Wilson, "The Ethics of Human Cloning" (American Enterprise Institute Press), and has just completed a study of the biblical book of Genesis.
Kass grew up in Chicago. His parents were Yiddish-speaking, Eastern European Jews. "It wasn't a religious household," he said. "But there was reverence -- if not for God, for human life. My parents were socialists. I learned later that their socialism was in the moral spirit of the Jewish prophets -- not Marxism."
Kass adds, ruefully, "I didn't realize how much moral passion there is in the Jewish tradition. I'd have been a rabbi if I'd lived during the time of the czars."
His interest in bioethics developed "indirectly," Kass said, when he was a graduate student and he and his wife, Amy, returned to Harvard after spending the summer of 1965 doing civil rights work in Mississippi. "I was puzzled," he said. "Why did I find more decency in the black farmers there than in the privileged graduate students? If the teaching of the Enlightenment was correct -- if you removed poverty and superstition, you would give people the opportunity to be moral human beings. But the graduate students around me were self-promoting."
Kass said that during this period he realized that "the advances made in science and technology to relieve suffering could dehumanize us." Advances in reproductive biology such as in vitro fertilization, he said, can do much good. Yet, he argues, these biotechnologies may also cause us "to lose our awe and mystery at the coming into being of a new life."
Emphasizing that he does not speak for the bioethics council, Kass said he opposes both cloning for research and cloning for human reproduction. Proponents of cloning assert that cells cloned from embryos may be able to provide knowledge of or treatment for diseases such as Parkinson's disease or diabetes.
To this Kass responds, "(with cloning) you can create a beautiful world. Where there's no disease, suffering, grief or despair. At a cost of stunted humanity. Where these problems are solved. But where human beings lack art, religion, self-government."
There are two types of bioethicists, Callahan said. "Most in this country are concerned with public policy -- with regulation. Such as, say, the rights of dying patients. A smaller number are concerned with broad questions: What does it mean to be human? What is the goal of medicine?"
Kass, he said, is among those who ask the "ultimate" questions. "Kass is a terrific teacher," Callahan added. "He wants to hear both sides of the argument. Though on issues like cloning, Kass has a position. He can work with Washington."
Kass is highly regarded by other bioethicists, even those who are his critics. Ronald M. Green, director of the Ethics Institute at Dartmouth College, speaks for many when he says of Kass: "I disagree with many of his conclusions. But I think Leon Kass has been extremely intelligent and thoughtful. He plays an important Cassandra role. We've seen terrible abuses in the quest for biological perfection (for instance, eugenics) and the over-medicalization of our world. Kass helps us to move forward with our eyes wide open."