Leon Kass was born in Chicago in 1939 to a family of Jewish immigrants. His childhood home was "Yiddish-speaking, nonreligious, lower middle class." At age 15, he was admitted to the University of Chicago where, he recalls, "I did very well on my science placement tests so my adviser made me a science major."
He entered University of Chicago's School of Medicine upon graduation, but not before "acquiring a prejudice in favor of reading old books slowly, a certain taste for philosophical questions, and a keen interest in liberal education."
While he was a medical student, he met and married his wife of nearly 52 years, the classics scholar Amy Kass. The couple went on to Boston, where he completed an internal-medicine internship and earned a biochemistry Ph.D. at Harvard.
"A funny thing happened to me in graduate school," he recalls. "My wife and I spent part of the summer of 1965 in Mississippi doing civil-rights work." The couple lived with a black farmer in Mount Olive, Miss., in a home that had no toilet or indoor plumbing. "I came back from this place with this conundrum: Why was there more honor, goodness and decency in these unschooled black farmers than I found in my fellow graduate students at Harvard, whose enlightened and liberal opinions I shared?"
The answer, he eventually concluded, was that his black hosts displayed "the dignity of honest work and religion"—things he didn't often find among his highly educated peers, most of whom "were only looking out for Number One."