In August 1865, Franz Liszt asked his daughter Cosima to come to Budapest for the premiere performance of his oratorio, "St. Elisabeth." At that time, she was still married to conductor Hans von Bulow, though her third child, 4-month-old Isolde, had been fathered by Richard Wagner. The affair, which would reach its conclusion five years later with the marriage of Wagner and Cosima, had started innocently enough in 1857, while Cosima and von Bulow were still on their honeymoon, and had begun its most intense phase in the summer of 1864.

Cosima's trip to Budapest lasted five weeks -- Liszt had an inkling of the clandestine relationship and was deliberately trying to separate the lovers and turn his daughter's mind "to other thoughts." Back in Bavaria, during this separation, Wagner's mind was turned to thoughts which fill the earliest section of the "Brown Book," a gem-studded, calf-bound notebook that Cosima had given him a short while before to use as a sort of diary and a means of communication. When they were apart, he was to write his thoughts in it for her to read later. Much of what he wrote in that August and September has never been previously published -- and looking at it, one understands why.

Parts of the Brown Book, which is now published complete for the first time, have been basic elements of Wagner scholarship for as long as Wagner scholarship has existed. A few sections have been lost forever, like much of Wagner's correspondence, through his family's concern for the image of a man who was not always careful about what words he put on paper. His daughter Eva cut out and destroyed 14 pages of the Brown Book before giving it to the town of Bayreuth in 1931, and she pasted paper over five other pages to make them illegible -- but this work was carefully undone, in the name of Wagner scholarship, in 1974.

These pasted-over sections, and others not previously published, add nothing substantial to knowledge of Wagner's life and work, but they do present some glimpses of the seamy side of genius. They leave the impression that Richard Wagner was more or less like the rest of us when he was upset, lonely, thwarted or frustrated -- and perhaps that is something worth knowing for those who didn't suspect it before. In a sense, such revelations diminish Wagner's stature; he is shown as a crybaby, a petty-minded, enormously self-centered man prone to excursions of wild fanaticism and capable (in a pre-freudian age of innocence) of putting on paper some shockingly self-revelatory symbolic free associations. But the image straightens out again when you reflect that this egocentric, peltulant, obsessed infant managed to write the words and music of "Tannhauser," "Tristan" and "Meistersinger" -- not to mention the Ring Cycle.

Wagner used the Brown Book as a diary, to be shared with Cosima, for only a few years. Her name covers the early pages like a rash, but the last item addressed to her appears on Feb. 17, 1868, by which time they were together almost constantly and had no need of written communications. After that, Wagner very practically used the blank pages for notes and first drafts of many of his writings in prose and verse, an occasional musical motif, outlines of some abortive projects and an occasional obituary memento of a deceased friend. There is now and then a venting of spleen in these later pages -- for example, an angry eight-line poem about the botched Munich premiere of "Rheingold," an oblique slash at the critic Hanslick in the notes for an essay on Beethoven -- but the tone is, on the whole, calm, the image that of a public man who senses posterity looking over his shoulder.

Not so the summer of 1865, when the book was new, and Wagner was deprived of his mistress. In a sense, the writer is on stage in these passes, too; they were written to be read by another, and the rhetoric is often shaped for Cosima's eyes, but it presents a Wagner sadly different from the Olympian contriver of the epic Nibelungen cycle.

At the beginning, he is self-consciously poetic, describing the climax of his climb up a mountain: "Above the edge of the mountain, I caught sight of the first brightly twinkling star. . . . I took it for the evening star and hailed it loudly -- 'Cosima.'" But a few days later, the mood has changed: "Sick and wretched. Bad cold: fever! Lonely here," and the door is opened for self-pity: "She does not understand me! . . . It doesn't occur to her how bitterly I suffer from her being far away." There are moments of lucid self-examination: "I am, I'm afraid, still always too passionate in all that I do -- even my work."

In one lucid span of several days, Wagner set down in the Brown Book a first draft of a summary of "Parsifal" for his patron, King Ludwig II of Bavaria. But a few days later (in the privacy of his diary) he was calling the king "childish" -- a true enough statement, but one he would hardly have dared to make in public. Liszt, his artistic patron, guide and protector, fares no better; he is, after all, a prospective father-in-law, and he is keeping Wagner from his love on the pretext of an oratorio premiere. "Your father is repugnant to me," he writes, "and when I was able to bear him there was more Christianity in my blind indulgence than in all his piety."

Reading them more than a century after they were written, there are two passages in this section that have specially chilling overtones, surrounded as they are by the moanings of a deprived lover. The jump from Sept. 1 to Sept. 2 is particularly suggestive. After ending one day's diatribe with "Don't talk to me of your love!!" he begins the next day's with "What to do about the blood-stained lance?" and under the guise of a calm discussion of a key motif in "Parsifal" he launches into an unwitting excursion into Freudian symbolism.

Even more chilling, in light of the Nazi era and its veneration of Wagner, is another passage. Inspired by a newspaper picture of an old man, he launches into a hymm to German identity: "See this head of Riemann's. This is the German ideal. Quite indescribable! Little emotion, no Hungarian, Polish or French flexibility, somewhat ponderous, ungraceful; but that thoughtful disposition! The naive gaze, the strange faith it contains, the fanaticism! . . . All so fantastic that no human being can grasp it. But I did. Now it is me no one grasps: I am the most German being, I am the German spirit. Question the incomparable magic of my works, compare them with the rest: and you can, for the present, say no differently than that -- it is German. But what is this German? It must be something wonderful, mustn't it, for it is humanly finer than all else?"

Look deeply enough into any human soul, choose to focus on particular aspects of the complex reality, and the reaction must be terror and disgust. Perhaps our international monuments like Richard Wagner should be spared this kind of scrutiny -- but more likely it is good for us to know that they, too, were made of our common clay.

In the case of Wagner, this is hardly a new revelation; the basic facts were well-known even in his lifetime, and Professor Bergfled's impeccably prepared, thoroughly and helpfully annotated volume adds only a few details amid all its new documentation. But it is good to have all that can be known about a genius readily available, and by gathering the whole of the Brown Book between a single pair of covers he has made easier the task of those who wish to study in depth the soul and the work of Richard Wagner.