In the forties and fifties, when the most gifted defenders of humanism were counting up the “costs” of modernity—uncertainty, ambiguity, alienation—Popper was arguing that these things were exactly what allowed science to tell us plain truths and give us great gifts. The growth of knowledge begins in uncertainty, and increases it: it opens more questions than it answers, and is possible only through the institutionalization of doubt. Anxiety is fruitful. All you need for liberty to continue is a tradition of seeking out criticism. In the Louvre for the umpteenth time, I looked at Castiglione’s smile and was reminded of the serenity this belief must bring to the man who held it.

A few days after my return to Oxford, I got on a bus to High Wycombe, in Buckinghamshire, which was the nearest stop to Popper’s home, in the hamlet of Penn. (I didn’t record, in the notes I made later about my pilgrimage, exactly what I said in my letter to the great man, but I had somehow wangled an invitation.) I recalled something that he had written in his autobiography, “Unended Quest”: “It was after our first visit to America that we moved to Penn in Buckinghamshire, which was then a quiet and beautiful little place.”

Popper had told me on the telephone to take a taxi from the bus depot, and the cabdriver, a Pakistani, I think, reacted immediately when I gave him Popper’s address.

”Ah, Professor Pop!” he said. “A very smart man.”

”You’ve met him?” I asked.

”Oh, many times. He never talks. All the time he is busy thinking, thinking.”

”His books are very famous.”

”I tell you, this is no surprise to me. People going to pay good for all that intelligence.”

We drove up to Popper’s cottage, and I knocked on the door. In “Unended Quest,” Popper wrote that one of his first memories was feelings of admiration for his cousin Eric Schiff, “whom I greatly admired for being one year older than I, for his tidiness, and, especially, for his good looks: gifts which I always regarded as important and unobtainable.” Good looks as an important gift, like a gift for writing or for thinking—it had seemed a strange idea to me at the time. But now I got it. Popper was a small, unimpressive man, several inches shorter even than I was—and I was a pipsqueak—and his long, solemn face was bracketed by a pair of elephantine ears. He was wearing a gray sweater, gray trousers that were too large in the seat, and a white shirt, missing a button from the left cuff.

The house led to a terrace that led to a small and straggly garden, with a scrawny, expiring apple tree.

”It’s pleasant here,” I said politely.

”Once it was pleasant here, but no more,” he replied, shaking his head. An airplane hummed overhead and he looked at it as though it were an unrepentant Hegelian. We stood at the terrace door.

”I have something I wish to show you,” he said abruptly, and he disappeared into the house. I stared blankly at my notebook full of high-minded questions. The sky looked threatening.

”Here,” he said, coming back with two new books in his hand. “I have just received these in the mail this morning.” One of the books was called “A Critique of Karl Popper’s Methodology,” by a certain Ingvar Johansson. The other one was in German. I opened the Johansson book and, at Popper’s urging, read the inscription. “To Sir Karl with admiration, I. Johansson.”

”Do you know Johansson, sir?” I asked.

”No, no.” He took back the book and began to flip desultorily through its pages. “It is another attack, no doubt. You know, people do not distinguish between intellectual criticism and personal attacks. I don’t receive criticism. They think it is enough to call me a fool.”

”Oh, surely no one does that,” I protested.

He smiled sadly. “All of my students are attacking me now. Three of my students, all of them I helped to get positions, to get chairs, and they know this, and still they attack me personally. You know, when you do things for people there are two types of reactions. There are those who cannot forget you for it and those who cannot forgive you for it. Do you see?”

He returned to thumbing through the book by Johansson. “He has read nothing of mine, of course. He will then attack this imaginary Popper. Since he already knows what is contained in my works, he need not read them, you see.”

”Tell me,” I said, “what criticism have you received in your career that has helped you—that you regard as really useful?”

He stared off for a long moment. “None,” he said. “I have never received any of this kind of criticism.” He looked away again. “Come. Let us go into the house.”

The living room was large, and nearly empty, except for a grand piano in one corner. Six or seven small Rembrandt reproductions were hung around the room. We sat down in armchairs, with a table between us, and I realized that Popper was rather deaf; for the next four hours, as we spoke, he would cup one of his enormous ears and press it toward me. We talked, interrupted only by Popper’s rising, at key moments, to go and fetch some book that he had mentioned and plop it down on the table. It seemed that for him the books were the reality; that the discussion about a book could not continue unless the book, the Real Presence, was at hand.

It is difficult to convey, after all these years, the vehemence with which he put forth his views—the silly, the profound, the trivial, and the deep. This was a man alive with resentments, vindictive anger, and persecution mania; at the same time, he had a kind of large-spiritedness, not remote from simple naïveté, that led him to open his door to a kid from Canada and fill him up with all his dogmas and doubts as though he were an old colleague.

Music—the great sequence that, for him, began with Bach and ended with Schubert—was his favorite art form, and he began to talk of his distaste for modern music. “It is terrible,” he said. “And this is one of the most interesting and encouraging phenomena of our time—the failure of the historicist propaganda for the modern in music.” Another famous book of his, “The Poverty of Historicism,” attacked the popular notion that history had a shape, a progression, followed laws of development. “We have been exposed to this propaganda for fifty years, and it has been quite unsuccessful,” he said. “There is something I must show you in this connection.” He got up again, went into the next room, and came back with Charles Rosen’s introduction to Schoenberg, a volume in the old Fontana Modern Masters series. (Popper himself had been a subject, in a short book by Bryan Magee.) He stood over me. “Read out the first paragraph of this book,” he insisted.

I read, “Arnold Schoenberg always thought of himself as an inevitable historical force.”

Popper grabbed the book from my hands and threw it down on the table. “Now, what has this to do with music?” he demanded. “We can wish to do our work well—but this wish to do work that is ahead of its time, this is nothing but historicist propaganda. Bach and Mozart never wished to shock people—they never worried about the ‘shock value’ of their work.”

I tried to turn the subject to books, and asked him if there were any contemporary writers he admired.

”There are a very few I have enjoyed,” he said. “The writer J. D. Salinger is the one I admire most. He has written one or two things that are quite good.” He got up, found a dog-eared copy of “The Catcher in the Rye,” and placed it on the table, where it joined Schoenberg and Johansson and the rest. “Yes, this is a very good study of adolescent psychology,” he said. “I do not care for his last book. Tell me, what has he published recently?”

I informed him that Salinger hadn’t published anything in a decade.

Popper stared off again. “Yes, no doubt he, too, was a victim of historicism.”

What iron had entered his soul? Twenty-five years later, I still don’t know. “Wittgenstein’s Poker” is full of similar testimony, about Popper’s ferocious temper and his inability to accept criticism of any kind. Even Bryan Magee, his most articulate popularizer, wrote, in a memoir, that “everything we argued about he pursued relentlessly, beyond the limits of acceptable aggression in conversation. . . . He seemed unable to accept the continued existence of different points of view, but went on and on and on about them with a kind of unforgivingness until the dissenter, so to speak, put his signature to a confession that he was wrong and Popper was right.”

The situation was straight out of Molière: the greatest living exponent of the value and necessity of criticism would fly into a rage at the least breath of criticism. In one way, Popper’s paranoia was a critique of his philosophy. People don’t welcome criticism. In fact, even scientists dismiss criticism and potential falsifications until someone builds a new edifice on the basis of the black swan. Popper believed that competing hypotheses fought each other off nobly while we watched; the reality is that competing hypotheses are mauled, and then one creeps away to die in peace. No one ever really changes his mind about anything; there are just more minds that think the new way. Behaviorism, Freudianism—no one refuted them, really. They just passed away out of loneliness.

In another way, his persecution mania wasn’t entirely unfounded. He had changed the climate of thought, but he had not changed the weather in philosophy departments. He felt cheated, and in a sense he had been. Although big ideas are meant to go from controversial to celebrated, in truth they more often go from contemptible to commonplace. “The earth is round!” someone says, and the world’s first response is “You’re mad!” and then, after someone takes measurements, “Of course it is! Who didn’t know that?” It’s a rule that applies with special force to Popper.

But what really underlay the contradiction between what he thought and what he was, I now think, after a quarter-century’s reflection, is a perversity of human nature so deep that it is almost a law—the Law of the Mental Mirror Image. We write what we are not. It is not merely that we fail to live up to our best ideas but that our best ideas, and the tone that goes with them, tend to be the opposite of our natural temperament. Rousseau wrote of the feelings of the heart and the beauties of nature while stewing and seething in a little room. Dr. Johnson pleaded for Christian stoicism in desperate fear of damnation. The masters of the wry middle style, Lionel Trilling and Randall Jarrell, were mired in sadness and confusion. The angry and competitive man (James Thurber) writes tender and rueful humor because his own condition is what he seeks to escape. The apostles of calm reason are hypersensitive and neurotic; William James arrived at a pose of genial universal cheerfulness in the face of constant panic. Art critics are often visually insensitive—look at their living rooms!—and literary critics are often slow and puzzled readers, searching for the meaning, and cooks are seldom trenchermen, being more fascinated by recipes than greedy for food.

It is not so much that we are drawn to things that frighten us as that we are drawn to things that we can think of as things—as subjects that exist outside the boundaries of all that is just the way we are. It is not merely that we do not live up to our ideals but that we cannot, since our ideals are exactly the part of us that we do not instantly identify as just part of life. An original thought is like a death mask of a man, with the solids made hollow and the nose a cavity, a portrait pulled inside out. We are our ideas (Popper, with his long, slightly overformal sentences, lucid but unornamented by wit, sounded like Popper, and no one else), for they include everything we are—but turned right around to face us, and looking back at us in surprise.

I stayed for two more hours. Popper held forth on the question of “big” science—technological science, the science that sent men to the moon and made hydrogen bombs. (“It is a myth that the success of science in our time is mainly due to the huge amounts of money that have been spent on big machines. What really makes science grow is new ideas, including false ideas.”) He recalled conversations with Albert Einstein in the fifties. (“You must understand that I learned nothing from Einstein directly, as a consequence of our conversations. He tended to express things in theological terms, and this was often the only way to argue with him. I found it finally quite uninteresting.”)

At the very end, as the winter light dimmed in that cold and cheerless way it does in England, I asked him what unsolved problems might still interest him. I suppose I was trying to raise his spirits. “In contemporary philosophy there are no such problems,” he said. “This is owing to the influence of Wittgenstein. As you know, Wittgenstein said that there are no philosophical problems, only linguistic puzzles. This has been the predominant attitude in Britain throughout my lifetime. As a result, there are no philosophers left, real philosophers who grapple with real problems. There are only professors who worry about words.”

He turned and looked out the window, over the wintry hills of a Britain denuded of philosophy. He looked, as Holden Caulfield might say, goddam depressed. By now, the pile of books between us, Salinger and Bellow and Johansson and Ernest Jones and Kuhn and Forster, well-thumbed paperbacks and old university textbooks and leather-bound volumes all mixed up, had risen until he almost disappeared behind it.

Ironically, Popper was on the brink of a false spring of fame. Many of the first generation of Thatcherite intellectuals admired him keenly, and pointed to him as a model. But British Toryism was unhappy with a too tightly argued position, while his brief romance with the right damaged his reputation with the social democrats. In the century’s last decade of liberal triumph, then, Popper’s contemporary Isaiah Berlin, who in the seventies had seemed too plummy and sonorous and lacking in fighting spirit for a hero, became the image of enlightened humanism. Popperians, now and then, tend to be suspicious of Berlin, since he had all the gifts Popper lacked, and, though unquestionably on the right, or same, side, let rhetorical grace do a lot of the work of hard thought. Berlin lifts the curtain, peeks at the irrational, and then quickly closes it again, with a reassuring bow to his audience. It is squalid in there, but, fortunately, not too squalid to bear.

Yet Berlin, too, we now know from Michael Ignatieff’s biography, was the man his thought denied. The news his work provides that liberal humanism is superior precisely because it can encompass the humanity of even those who are most anti-liberal was a revelation. But it left him divided. He ended up believing in his head that the ideas of the good life could not be reconciled, and in his heart that they could all be reconciled in one genial temperament, or at one great dinner party. His charm and social curiosity—which, according to his biographer, flowed from his sense of insufficient accomplishment, as Popper’s charmlessness flowed from his sense of thwarted recognition—ended by having a political meaning: though thoughts were not reconcilable, thinkers were, or might be. (It is an awkward truth that social life is the antidote to scholarly paranoia; it drains intellectual differences of their drama. The cure for the acrimony of intellectuals is dinner. Had Jesus invited a few Pharisees over for the Supper—and the Pharisees, let us remember, had been revolutionaries only a little while before—it might not have been his last. Dining with disciples is a perilous business.)

Between the heart and the head lies the soul, and soulfulness is not the least thing we ask of thought and thinkers. Liberal humanism, as much as it is a theory, is a style—even, at moments, a look, an appearance—of openness turned inward, social tolerance, geniality writ large; my naïve instinct that the civilized spirit was represented by Castiglione’s smile had a drop of truth in it. Popper’s philosophy, I now think, explained everything but Popper—left no room for the forces of ambition and attraction and jealousy and rage that governed his own life. His philosophy, so rich in so many other ways, did not allow for that kind of human perversity, or for his own doubleness. It was humane but inhuman.

I went to the British Museum the day after I returned from my pilgrimage, and happened to come across the vase that Keats wrote his ode about. Well, I thought, looking at the thing, so truth is not a black swan gliding, or a bunch of dancers dancing. Truth is an ugly duckling with big ears, truth is whatever it may be, and beauty is whatever it may be, and they are not the same, not at all, not even close. That urn had it all wrong. I knew that much now, and for sure. ♦