Kass is best known as a proponent of liberal arts education via the "Great Books," as a critic of human cloning, life extension, euthanasia and embryo research, and for his tenure as chairman of the President's Council on Bioethics from 2001 to 2005.
"For his students and readers," Yuval Levin summarizes, "Leon Kass has laid out a path of inquiry showing that those questions that bedevil us most today have been with us for countless generations, and have to do not with the latest modern excess, but with man’s unchanging nature, wants, needs, and potential.
[7] Around this time Kass began to develop an interest in morality in medicine and in bio medical ethics, instigated partly as a result of reading Rousseau's Discourse on the Arts and Sciences.
They visited many families in the community, participated in their activities, and helped with voter registration and other efforts to encourage the people to organize themselves in defense of their rights.
"[13] Later that fall, Kass wrote a letter to his family and friends detailing his and his wife's experiences and appealing to them to donate to the Civil Rights Movement.
[13] The character of the rural, poor, and uneducated African Americans with whom they lived and worked contrasted with his colleagues at Harvard and other elite universities.
Why, I wondered then, was there more honor, decency, and dignity among the impoverished and ignorant but church-going black farmers with whom we had lived than among my privileged and educated fellow graduate students at Harvard, whose progressive opinions I shared but whose self-absorption and self-indulgence put me off.
His early interest in bioethics was stimulated by Aldous Huxley's Brave New World and C. S. Lewis's The Abolition of Man, both of which he read at the suggestion of Harvey Flaumenhaft.
"[6] In 1967, Kass read an article by Joshua Lederberg in the Washington Post suggesting that humans could one day be cloned, permitting the perpetuation of the genotypes of geniuses.
[16] In a letter to the editor, Kass made a moral case against cloning and suggested that "the programmed reproduction of man will, in fact, dehumanize him.
"[7] Thus began a second career of writing on bioethics, including essays on organ transplantation, genetic screening, in vitro fertilization, cloning, the conquest of aging, assisted suicide, medical ethics, and biotechnology.
At St. John's, Kass taught in the Great Books program as well as in-depth studies of Aristotle's De Anima and Nicomachean Ethics and Darwin's On the Origin of Species.
At the University of Chicago, Kass taught courses across the humanities and sciences, including both undergraduate and graduate seminars in the Nicomachean Ethics, Plato's Symposium and Meno, Lucretius, human passions, science and society, Rousseau's Discourse on the Origin of Inequality, Genesis, Darwinism, Descartes's Discourse on the Method, classical geometry, Tolstoy's War and Peace, marriage and courtship, Exodus, and biotechnology.
In his 1992 article "Regarding Daughters and Sisters", an examination of the Biblical story of Dinah, Kass writes that "rape is a capital offense, a crime worse even than murder.
He concludes:Many lonely women, more than can safely admit it, secretly hope to meet a gentleman; but the vast majority steadfastly refuse to be ladies—indeed, no longer know what it means.
But, addressing the symptom not the cause, the remedies of karate and “take back the night”—and, still more, the shallow beliefs about sexual liberation that support these practices—can only complete the destruction of healthy relations between man and woman.
Many scientists were advocating the removal of limits on embryonic stem cell research, but critics expressed concern about what they characterized as the wanton destruction of human life.
"[20] As the council was appointed and prepared to begin meeting in early 2002, Kass received a great deal of media attention, especially due to his reputation for pessimism and concern about the moral implications of scientific progress with respect to health and life issues.
The first specific task of the council, according to the executive order creating it, was "to undertake fundamental inquiry into the human and moral significance of developments in biomedical and behavioral science and technology.
"[26]) Also, the council members Robert George, Francis Fukuyama and James Q. Wilson debated with stark disagreement their opposing points of view on the biological status of the human embryo and came to no agreed conclusions.
"[29] Despite the public's narrow conception of its work, during Kass's chairmanship, the Council produced five book-length reports, a white paper, and a humanistic reader on ten topics generally neglected in the bioethics literature.
He sought a "richer" inquiry that debates "ends as well as means," and the council's reports addressed larger human questions, "not merely administrative or regulatory ones."
"[29] Eschewing much of the language and theoretical framework of academic bioethics,[25] Kass drew on literary, philosophical, and theological sources to inform the council's discussion.
[36] Robert P. George praised Kass as the driving intellectual force against embryo-killing and in favor of finding alternative methods of obtaining pluripotent stem cells: "All along, it was Dr. Kass who said that reprogramming methods would, if pursued vigorously, enable us to realize the full benefits of stem cell science while respecting human dignity.
"[34][38] In response to Kass, other ethicists have argued that reactions of repugnance or disgust are not a valid basis for banning cloning because such feelings are subjective, dictated by cultural norms, and change over time.
"[39] Martha Nussbaum has advanced a broader argument against using feelings of disgust as a basis for policymaking, writing that "laws and social rules" should be based on "substantive harm, rather than on the symbolic relationship an object bears to our anxieties.
"[40] In addition to opposing cloning on the grounds of repugnance, Kass has also argued that cloning constitutes an "unethical experiment upon the resulting child-to-be"; creates confusions of identity and individuality; "turns begetting into making"; and, by giving parents control over a child's genetic make-up, exacerbates the "dangerous" idea of parental control over children's lives and prospects.
In addition to his studies in natural philosophy and philosophical anthropology, Kass has in recent years been teaching and writing about the Hebrew Bible, especially the book of Genesis.
Kass's interest in the Bible began with weekly invitational readings of Genesis that he and his wife, Amy, had organized for students while teaching at the University of Chicago.
God "exists" only in the minds and actions of people who feel awe and reverence in their experience of "the ecstatic passions of Dionysus" elicited by religious ceremony (430).