Rainer Maria Rilke was not only one of the great poets of the German language, he was also one of the great correspondents of all time. During the last few weeks before his death from leukemia, he had cards printed to say that he regretted that he was forced by his illness to neglect his correspondence. The cards were sent to more than 100 people.

Several volumes of Rilke’s letters are in print in English, and at least two can be considered classics: the “Letters to a Young Poet” and “Letters on Cezanne.” But surely one of his most significant exchanges was his correspondence with Louise Andreas-Salome, published for the first time in English as “Rainer Maria Rilke and Lou Andreas-Salome: The Correspondence” (W.W. Norton, 424 pages, $39.95), edited and translated by Edward Snow and Michael Winkler. Mr. Snow is a highly regarded translator of Rilke’s poetry and Mr.Winkler is his colleague at Rice University in Houston. Their translation is immensely readable and the book is a significant piece of scholarship.

Rilke left no thought, no impression, no vagrant sensation unexpressed. He had to write it down, had to tell her, or whoever his recipient was, everything. He desired “that my mouth,when it has become a great river, may one day flow into you, into your listening and the great stillness of your opened depths.”

Andreas-Salome was surely one of the most remarkable women of the late 19th and early 20th centuries. She was a novelist, a dramatist, a literary critic, a student of philosophy, and finally one of the first women, at the age of 50, to become a psychoanalyst. Freud referred to her as an “understander par excellence.” She was extremely productive, in spite of frequent ill health – in a diary fragment reproduced in this book, she refers to “the rapture of work.”

When she was young she was a student of Nietzsche’s, who was so completely captivated with her that he proposed marriage. She declined, yet she did live in a kind of menage a trois with Nietzsche and Paul Ree, a philosopher of morals.A menage of trois minds, one must suppose. Nietzsche even thought for a while she would become his philosophical heir.

Lou, as she is referred to throughout the book, was an early feminist and lived a life untrammeled by convention. She was strongly opposed to marriage, though she remained married to her husband Carl Friedrich Andreas, for 43 years, on the condition that they abstain from sex.

Lou, meanwhile, engaged in numerous extramarital relationships, one of which was with Rilke. When they met in May of 1897, he was 21 and she was 15 years his senior. For the next four years they spent nearly every day together. It was Lou who persuaded Rilke to change his name from Rene to the more masculine and more German sounding Rainer. They traveled to Russia together twice and met Tolstoy. They shared a love of Russian literature. (Lou, a Baltic German, was born in St. Petersburg.) But after four years of what Messrs. Snow and Winkler refer to as his “morbidly monopolizing fixation on her,” she had had enough and longed for nothing so much as quiet and, as she put it, “more being by myself, the way it was until four years ago.” She was disturbed, as well, by his extreme mood swings. Rilke’s impending marriage to Clara Westhoff, whom he had met at the artist’s colony at Worpswede near Bremen, further aided the breakup.

Yet their mutual fascination did not end, and, though there is a hint of the romantic and the erotic in their letters, she became for him a kind of guide through life, a mother figure.

Rilke proved to be a poor husband to Westhoff and father to their daughter, Ruth. He left them when he became secretary to Auguste Rodin, and they never lived together again. His relationships with women followed a pattern: He fell deeply in love, wrote passionate letters and poetry, and then, when they became too close, he left them and embraced his solitude, asking them to do the same.

W.H. Auden mocked Rilke, calling him the “Santa Claus of loneliness.” But Rilke saw his solitude as necessary to him as an artist. “If anyone ever needed seclusion, it is I,” he wrote to Lou. He was an artist above all else, but he was less successful at life. Of his difficulty, he wrote:

I don’t want to sunder art and life; I know that sometime, somewhere, they must agree. But I am all thumbs at life. … For art is something much too big and too difficult and too long for one life, and those who have entered a great old age are only beginners at it.

Rilke had a great fear of psychoanalysis, thinking it might undermine the sources of his art. Yet he almost succumbed to the idea.To Lou he wrote,

I know now that analysis would make sense for me only if I were truly serious about that strange thought at the back of my mind – no longer to write. … Then one might have one’s devils driven out, since in ordinary bourgeois life they are really only bothersome and awkward anyway, and if by some chance the angels left with them, well, one could view that too as a simplification and tell oneself that in one’s new, one’s next occupation (but which?) there would certainly be no useful place for them.

But Lou, in spite of her belief in psychoanalysis, strangely discouraged him. Messrs. Snow and Winkler surmise that it was because some of his secrets were also her secrets, and she did not want them disclosed to Rilke’s chosen analyst, Viktor Emil von Gebsattel, a colleague of hers.

Yet she did recognize that out of the conflict between his “devils” and his “angels,” Rilke created great art, which established its own equilibrium and sense of wholeness. In a letter to him, Lou wrote, “You are in pain, and I, through your pain,feel bliss.Forgive me for that.” And she noted in her diary,

Something behind all this is continuing, calmly growing to perfection, while he, to whom it is happening, suffers almost without respite and is forced to doubt. For me it was a daily source of happiness and made me as free of worries about Rainer as I have been.

As in any correspondence, there are longueurs. But there are also passages of great beauty, of artistic and psychological insight. We feel Rilke’s exultation upon finishing the 10th Duino Elegy in a rush of afflatus, “Think of it! I have been allowed to survive until this. Through everything. Miracle. Grace, – All in a few days. It was a hurricane … all that was fiber in me, tissue, framework, groaned and bent.” And we realize how much their relationship meant to Lou, even toward the very end, when she wrote:

Now it’s over, and I won’t see you anymore. I must always remind myself that the magic of our subterranean connection does remain with me, and that it would persist even if neither of us were to be aware of it. But I didn’t tell you even once what it meant to me to feel such connectedness enter my bright day, such hour-by-hour reality of knowing you were only a few streets away.

The correspondence is the record of the remarkable relationship, lasting more than 25 years, of two remarkable people.

Mr. Volkmer last wrote for these pages about the lost books of history.