There are teachers and there are professors. To be a professor is to profess, to impart by virtue of one’s superior wisdom and authority the knowledge that one has and one’s students do not. The insights given by a great professor are a privilege to receive. To be a teacher, by contrast, calls for more ingenuity and patience; it is the canny art of coaxing insights out of the students themselves—a “midwife to knowledge,” as Socrates would have it. With wisdom and authority to spare, Amy Apfel Kass, who passed away on August 19, could easily have been a great professor. Instead, she was the greatest of teachers.

Born in New York in 1940, she was a bright light at the University of Chicago for 34 years, also teaching at St. John’s College in Annapolis and in various programs of the Hudson Institute in Washington. Notwithstanding these elite affiliations, she was democratic in her means and aims, a defender of the liberal arts as a heritage that belongs to and benefits everyone, with a sneakily elemental way of bringing them to life.

When I met Amy—then “Mrs. Kass”—I was a freshman who had crept into her class on King Lear where I did not belong, hoping she would sign my registration slip. She sternly admonished me that this was a class meant for experienced students who would all be held to the same high standard, as I turned myself inside out promising to make every effort to meet it. She peered down her nose at me, her face impassive but her eyes dancing. “I believe you,” she said.

What followed was a transformative experience. Her standards were indeed high, enforced by a finely calibrated nonsense detector, but raised by an even more finely calibrated radar for a promising line of thought. “Another sentence, please,” was her frequent rejoinder: You haven’t made your case yet, but I sense you have one in you. All the same, you needed both humility and pluck to make it. Naming no names, I knew one cowering student who always made a point of sitting next to her so as to avoid her penetrating stare from across the room. That stare could plow the earth out from under you if ever directed that way with disgust. But it never was—at most, with disbelief, and a pointer back to solid ground. Indeed, although she might be said to “never suffer fools,” she was always suffering fools, driven by a bottomless ambition that we could think and be so much better than we knew. Her eyes lit up with a kind of knowing surprise every time that faith was rewarded, as if she expected no less but still marveled at what was said.

As for the course’s content? That one tragedy, just the one, mined for all the treasure it holds. Is there even enough to go on, you may ask, twice a week for months in a single Shakespeare play? Oh yes. Why does Gloucester begin with such a crude and blustery introduction of his bastard son, and why does it matter? What does Kent’s response say of his character? Does Lear’s plan to divide his kingdom make any sense? What is he trying to accomplish or avoid? Why does he force the “love test”? How can Cordelia fail to answer? Why does Lear not see what is so plain to everybody else, and find a way to backtrack before disappointment gives way to disaster? And that’s just the first half of the first scene. At the conclusion of the term, by popular demand, we convened for a bonus session to return to the problems posed at the start. We felt like now we were ready to begin our study of this dark illumination of family, power, and mortality. We were learning to read.

An added benefit of this and many of her other classes was the habitual presence of her partner in all things, Leon Kass, resulting in what she self-mockingly (but accurately) would sometimes refer to as “the Amy and Leon Show.” They always sat directly across from each other, while an invisible line between them crackled with tangible energy, like some kind of superstring from outer space. This was the marriage you wanted to have, if you only knew that such existed. Best of all was when they disagreed—not only for the spectacle of a good-humored literary squabble, but because it showed the students that multiple perspectives really were defensible, and because the engagement between them energized the text and led to deeper understanding. (That said, she usually “won.”)

In the beginning, or close enough, a young Amy Apfel enrolled at Antioch College, where she “spent the better part of a year folk-dancing.” Through Antioch’s internship program, she got a job at Chicago’s Museum of Science and Industry. On her first lunch break, she walked over to the University of Chicago’s admissions office and submitted a transfer application, then called her parents to tell them where they could reach her from now on.

On her matriculation at Chicago, two fateful events happened in short order. First, she went to a party for new students hosted by a committee devoted to keeping the spirit of inquiry at the college alive; among its members was the 19-year-old medical student Leon Kass. Second, she enrolled in the legendary Karl Weintraub’s course on Western civilization (students used to camp outside his office overnight in order to attend). Years later, she would say her mental reference for the “air of authority” embodied by King Lear was Mr. Weintraub.

One day she reported to him for a meeting. “So, Miss Apfel, what are you going to study in graduate school?” he growled. She stammered her way through the interview and withdrew, then pulled aside a passerby out on the quad. “Excuse me, what is graduate school?” she asked. In the Apfel family, one went to medical school. But in time, the answer to his question turned out to be the history of ideas and the purposes of the modern liberal arts movement, the foundation for the curriculum she would dedicate her life to teaching. She traded clinical questions with determinable answers for perennial questions with inexhaustible answers.

Those questions were not the ordinary austere humanistic deep-think—is there free will, what is man in a state of nature, and so forth—although they would inevitably lead in a profound direction. But they took on a character of their own. An Amy Kass discussion might begin thus: In the Declaration of Independence—“When, in the course of human events”—what does it mean for human events to have a course? Do they? In Shakespeare’s Sonnet 116—“Let me not to the marriage of true minds admit impediments”—is it minds that marry? How? In the 1934 romantic comedy It Happened One Night, what is the “it”? Setting the tone with such a query was an invitation to read closely, to attend to the subtleties of what’s in front of you, rather than pursuing abstract theories into space, to not take what you thought you knew for granted, to uncover what in some sense you knew all along.

Alternatively, the introduction might not be so literal, but instead an open-ended prodding to creative reflections: What is the difference between an adventure and a voyage? What does it mean to be at war, or be at peace? Is “home” the place where you are from?

Or it might be a focused investigation into a particular character—a line of inquiry that, if not taken up with the first question, she would soon turn to as the discussion went on. Out of the classic five Ws and an H, Amy’s approach seemed to be that when you have a handle on the who, the rest will more or less reveal itself accordingly. But you may not ever get to the bottom of that who. “What a piece of work is a man,” as Hamlet says.

Part of the secret was that the who off the page was as important to her as the who on it. There is a popular quotation widely attributed to George Eliot: “It is never too late to be what you might have been.” Eliot never actually said this, but it’s a fair description of Amy’s position towards her students of all varieties, from tender and cocky undergrads on the brink of enormous life change to D.C. policy wonks shocked out of their stodgy habits of thought by a humanizing revelation. To be what you might have been: not a reference to a career reevaluation or other things that often are too late to change, but to the orientation of the soul.

It was among her deepest convictions that the works of great writers over time have the capacity to elevate our thoughts and aspirations—to encourage us to reason better, feel better, seek better, become better. Through such works, this education is available to everyone throughout our lives. A recurring theme of her Johns Hopkins dissertation on the liberal arts and the “Great Books” movement is that adult education has always been an important aspect of that project—not an afterthought or spin-off, but a major impetus. (The inspiration was the “People’s Institute” in turn-of-the-century New York City, where immigrants gathered in the thousands to participate in lectures and discussions.)

In that spirit, Amy’s own educational project encompassed both four decades of teaching undergraduates and a wide variety of other offerings for general dissemination. At the University of Chicago, she helped design a core class for freshmen, “Human Being and Citizen,” and a departmental major for students to investigate a question of their own—Why are democracies dangerous? What is a father? Should we have secrets?—across philosophical and literary texts.

For the last decade, she maintained a perch at the Hudson Institute, where her focus was philanthropy, civic life, and the American character—as known through story, speech, essay, and song. Through formal and informal reading groups, video conversations and movie discussion series, curricula, and anthologies, she encouraged private flourishing and public-spiritedness, one awakened thinker at a time. Meanwhile, she took as many wandering souls under her wing as she could fit.

A highlight of Hudson’s annual programming was the Christmas discussion that Amy, a very chosen member of the Chosen People, always led. Often with seemingly odd or bleak story selections for the season, she drew out the mystery of charity and renewal, and the idea that no one is beyond grace.

Another quotation, this one unmistakably Eliot’s, captures what it means to make your life’s work other people:

Her finely touched spirit had still its fine issues, though they were not widely visible. Her full nature, like that river of which Cyrus broke the strength, spent itself in channels which had no great name on this earth. But the effect of her being on those around her was incalculably diffusive: for the growing good of the world is partly dependent on unhistoric acts; and that things are not so ill with you and me as they might have been, is half owing to the number who lived faithfully a hidden life, and rest in unvisited tombs.

Fortunately Amy did not live a hidden life, and will not go unremembered. But she did not leave behind much of a paper trail or other monument to her achievement. One catches glimpses of what she was up to in her several anthologies—with her touch visible in their selections and the tantalizing little introductions to each—in recorded conversations, in the course of study she designed at the university she loved, and in the spirit animating her inseparable husband Leon’s much larger body of written work. But to see her true accomplishment, you have to look without and look within.

Out and about, there are the hundreds of sometime students for whom she was, as one eulogist at her service put it, “the teacher of our lives”—not just the teacher of a lifetime, but the teacher who showed us how to live. We received an inheritance from her that now belongs to our own students, readers, children, in incalculably diffusive and unhistoric ways.

Within, there are the voices of the choir invisible / Of those immortal dead who live again / In minds made better by their presence (Eliot again) with pulses stirr’d to generosity and thoughts sublime that pierce the night like stars. Having recommended this choir to us and trained our ears to hear it, she now joins it herself. The song goes on. Everything she meant for us to know and be is still there for us to discover and reflect and act upon. You can give birth without a midwife. I only wish we didn’t have to.

Caitrin Keiper, a graduate of the University of Chicago, is editor of Philanthropy.