In my late teens and early 20s I was a mystic. It was Blake and Shelley who induced those grand intoxications, and also Keats and Wordsworth and Coleridge. At New York University, where Thomas Wolfe had once taught freshman composition, his shade — O lost, and by the wind grieved, ghost, come back again! — sometimes still flickered. Dylan Thomas, not yet in his cups and not yet renowned, came to a handful of students in an ordinary classroom and chanted, as if to a hall of hundreds, The force that through the green fuse drives the flower, syllables instinct with divine afflatus. Meanwhile I was writing an undergraduate thesis on the Romantic poets, and though I knew neither the word nor the concept, I was at that time seriously antinomian. Nothing was distinct, or of its own indivisible nature, nothing was fixed, nothing was demanded: all was wavering spirit and intuition. Rapture and ecstasy, ecstasy and rapture! — these were imagination’s transports, abetted by the piercing sweetness of melancholy. The sage was withered from the lake, and no birds sang; or else they chorused thrillingly, like celestial choirs.

Besides being a mystic and an antinomian, I was also a believing monist: all things were one thing, watercolor worlds leaching and blending and fading into porous malleable realms. Yearning and beauty were the heart’s engines, shocking the waiting soul (mine, anyhow) into a pulsing blur of wonderment. In Xanadu, where Alph the sacred river ran, you might actually see the Blessèd Damozel leaning over the bar of heaven! As for where the Spirit of God dwelled ... well, where else but in you and me? (Primarily, of course, in me.) The Ten Commandments? In Xanadu nobody had ever heard of them.

At 24 I blundered, I no longer recall where or how, into “Romantic Religion,” a book-length essay — or manifesto, or scholarly credo — by Leo Baeck. His name, his stature, his personal history, his transcendent learning were all unfamiliar. That he was of that remarkable German Jewish generation which included, among many other humanist eminences, the historian Gershom Scholem and the philosophers Martin Buber and Walter Benjamin, I had yet to discover. Nor did I know that Baeck was a rabbi consumed, beyond the vastnesses of his own multifaceted tradition, by Greek and Christian thought; or that he was of that minute fraction of Jewish humanity to have come out of Theresienstadt alive. When I stumbled into the majesties of “Romantic Religion,” I was as one (so it seemed to me afterward) who had conversed with Socrates while ignorant of Socrates’ origins and identity.

Not that Baeck was Socratic in his tone or approach. The essay was a formidable looking glass. In a dissenting voice more analytic than scornful (though scorn seethed behind it), he told me off. For the romantic, he wrote, “everything dissolves into feeling; everything becomes mere mood; everything becomes subjective. ... Fervently, the romantic enjoys the highest delight and the deepest pain day after day; he enjoys the most enchanting and the most sublime; he enjoys his wounds and the streaming blood of his heart. ... Experiences with their many echoes and billows stand higher in his estimation than life with its tasks; for tasks always establish a bond with harsh reality. And from this he is in flight. He does not want to wrestle for his blessing, but to experience it, abandoning himself, devoid of will, to what spells salvation and bliss.” And again: “Everything, thinking and poetry, knowledge and illusion, all here and all above, flows together in a foaming poem, into a sacred music, into a great transfiguration, an apotheosis. In the end, the floods close over the soul, while all and nothing become one.”

In the hundred energetic pages of Walter Kaufmann’s translation from the German (Kaufmann was himself a Princeton philosopher), under headings such as “Ethics,” “Humanity,” and “The Sentimental,” Rabbi Baeck had me dead to rights. I had been surrendering my youth to Weltschmerz, to Schwärmerei, to Welttrunkenheit, all those unleashed Wagnerian emotions which, Baeck pointed out, Hegel had once dismissed as the displacement of “content and substance” by “a formless weaving of the spirit within itself.” The opposite of all that besottedness was “the classical, ethical idea of history” as manifested in “the Kantian personality who confronts us as the bearer of the moral law” — the law of act and deed that is itself “an essential part of that honesty which man owes to himself: the test of criticism.” Who could criticize a dream? And what was that dream but immersion in fantasy and illusion? “Ethics evaporates into exaltation,” Baeck declaimed. “Justice is to be reduced to a mere feeling and experience; the good deed is effected not by human will but by divine grace; man himself is a mere object and not a personality. The will becomes supernatural, and only concupiscence remains to man. ... Something more diametrically opposed to ethics than Romanticism would be hard to find.”

And reading on and on in a fever of introspection, I was beginning to undergo a curious transformation: not the spirit’s visionary turning, but one willed and chosen. I had become the Ancient Mariner — only in reverse. Gazing down at the water snakes writhing below, Coleridge’s mystical sailor is all at once seized by a burst of joyous sanctification: to his transfigured senses the repulsive creatures of the sea are now revealed as blessèd things of beauty. But I, pursuing passage after passage of Baeck’s reprise of the incantatory romantic — its transports and exultations, its voluptuously nurtured sorrows, its illusory beauty anchored in nothing but vapor — I came to see it all as loathsome, no different from those mindlessly coiling water snakes. What did it lead to? The self. What did it mean? Self-pride. What did it achieve? Self-delusion and delirium. That way lay Dionysus. I chose Rabbi Baeck.

More decades than I wish to admit to have fled away since I first looked into “Romantic Religion.” And just recently, when I revisited my old copy — battered from many coerced lendings (it was I who did the coercing), and almost always returned unread — I was still impressed by its bold intellectual and moral cogency. But its power seemed somehow diminished, or, if not exactly that, then a tiny bit stale. I had, after all, assimilated those ideas from multiple sources over the years (not counting the Bible), and by now they were locked, as we have learned to say, into my DNA. “Romantic Religion,” with its emphasis on humane conduct over the perils of the loosened imagination, remains an essay to live by. It is not an essay to write stories by; stories crave the wilderness of untethered feeling. But once — even though I wanted then more than anything on earth to write stories — it left me dazzled and undone.

Cynthia Ozick’s most recent collection of essays is “The Din in the Head.”

Copyright 2006 The New York Times Company