It looks simple enough. The head of Charlie Brown is a circle, more or less, with little ears outcropping. A few quick lines spell out his face. But there is a mystery to it. Other cartoonists testify that it is difficult, maybe impossible, to duplicate the flow of Charles M. Schulz's pen. Anyone else trying to draw Charlie Brown will produce something a bit shabby or grotesque. "He always comes out looking so wrong," as one artist puts it, "a lurid joke, like someone dressed up at a costume party."

The final "Peanuts" strip appeared in February 2000, just after Schulz's death. He had been drawing it for not quite five decades - in which time Charlie Brown and company became among the most recognizable, not to mention profitable, characters on the planet. But Schulz had somehow transcended both entertainment and brand-recognition. He created a little world, and did so with a deceptive simplicity of expression.

Introducing the first "Peanuts" collection in Italy, the cultural theorist Umberto Eco put it best. "If poetry means producing from everyday, which we are accustomed to identify with the surface of things, a revelation that causes us to touch the depth of things," he wrote, "then, every so often, Schulz is a poet."

Everyone knew that he put a great deal of himself into the strip; he said so himself. In one interview that David Michaelis quotes in Schulz and Peanuts: A Biography, the cartoonist indicated that the pace of doing a daily strip had made constant introspection absolutely essential. "You survive only by being able to draw on every experience and thought you've ever had," Schulz said. "That is, if you're going to do anything with any meaning. Of course, you can grind out daily gags but I'm not interested in simply doing gags."

But the confessional element in the strip went well beyond using Charlie Brown as a character giving voice to the cartoonist's own bafflement in the face of life. His biographer embeds "Peanuts" strips throughout the story of Schulz's childhood, early struggles, marriage, and international fame.

In many cases the situations facing his characters are echoes of events or feelings from his own life - alluding to them, but translating them into imaginary form. But at other times, the cartoons prove to be almost diary-like records of personal relationships. It seems that everyone who knew Schulz's first wife recognized her as the inspiration for Lucy. The average reader had no clue, of course.

Nor did the public understand all that was going on when, in the early 1970s, Snoopy fell in love with a beautiful young beagle with "soft paws" he met at the Daisy Hill Puppy Farm. We never got to see her, but could eavesdrop on Snoopy's thoughts about the long-distance romance - a series of cartoons containing endearments meant for a woman who was not, let's say, calling Schulz "you blockhead."

Such revelations (a kind of retroactive gossip) form only a small part of this book's interest, however. It is a psychobiography: an effort to read the character behind Schulz's characters.

In a strip that ran following his death, the cartoonist wrote an open letter to readers saying that "Peanuts" had been "the fulfillment of my childhood ambition." Michaelis takes this statement seriously - treating his career as the product, not only of talent, but of an intense commitment that formed very early in life.

So did the rest of his temperament: a shyness and deep sense of loneliness and insecurity. Charlie Brown really is a portrait of the artist as a young man.

We don't know much about the adults in Charlie Brown's family, except that his father is a barber. So was Carl Schulz, the father of "Sparky" (as the cartoonist was nicknamed early on). He had a workaholic streak, as Sparky later did, but not much capacity to express affection. The boy, an only child, was much closer to his mother, who nonetheless sounds like a distant and unhappy soul. Other relatives tended to needle one another with joking insults; and at family gatherings, his uncles would get drunk and beat each other up on the lawn.

Michaelis' reconstruction of Schulz's early years (most of them spent in St. Paul, Minn.) is the most repetitious segment of an otherwise very absorbing narrative. Still, it goes some way toward accounting for the reserved yet driven figure who emerges from this background - someone who gained a measure of confidence while in the Army during World War II, and who seems to have been a devoted father, but who never shook a quality of melancholy that was bred to the bone.

Some members of Schulz's family have complained about rather small factual errors in the book, and insist that Michaelis has failed to capture elements of Sparky's personality that they saw. He was not, they say, as gloomy or consumed with long-standing griefs and grievances as the biography implies.

But it seems to me that Michaelis has made every effort to show the complexity of the man - especially what can only be called his rather aggressive modesty. In conversation and interviews, he could project the quality of being a loser who had somehow just happened to create a cartoon empire that generated millions of dollars of revenue per year.

None of which would be of much significance, though, if he had not created work that is often beautiful in its simplicity and emotionally powerful in ways it can be astonishing to rediscover. Michaelis has a good eye for what was distinctive about Schulz's drawing, particularly in the context of other cartooning of the day.

"'Peanuts,' full of empty spaces, didn't depend on action or a particular context to attract the reader," he writes; "it was about people working out the interior problems of their daily lives without ever actually solving them." The situations and the artwork were presented with "an almost aggressive economy." He created a world in which childhood and adult experience somehow overlapped, conveying "what it was to be vulnerable, to be small and alone in the universe, to be human - both little and big at the same time."

Although Schulz himself was an evangelical Protestant who admired Billy Graham, his characters sounded like little existentialists. In one strip, Linus asks Charlie Brown if he has heard of the Beat generation. "Oh yes," replies Charlie Brown. "I'm a charter member!" Michaelis notes that in the 1950s and early '60s, many readers developed the same relationship with "Peanuts" that they did with the fiction of J.D. Salinger appearing at the same time.

And Snoopy was definitely a counterculturalist. He was "purely adolescent - grandiose, revolutionary, with a mind of his own and feelings to match," writes Michaelis. "Often, he acted like a very badly hurt person, except that, precisely because his innermost thoughts were open to view, his wound, and its shame, were open for all to see."

While Charlie Brown served as both Schulz's alter ego and a kind of Everyman figure, Snoopy gradually took shape as part of one's self. "The reader took the interior monologues for his own," as Michaelis puts it, "somehow coming to believe that he was hearing his own innermost jokes and quirks, worries and hopes."

There are enough moments in this biography that illuminate Schulz's work to make up for the occasional pages that simply repeat psychological formulae already pushed about as hard as they can be pushed. My only other reservation about Schulz and Peanuts is that it reprints no examples of his other artwork, though Michaelis does refer to it from time to time.

It would also be interesting, if not pleasurable, to see "Peanuts" strips another artist was commissioned to do when Schulz had a contract dispute with his syndicate in 1977. Once the issue was resolved, the "backup" cartoons were stashed in a vault.

"They were meant to remain a secret," writes Michaelis. "Word of their existence circulated for years at United Media, hovering between rumor and urban legend, and when at last one of Sparky's editors came across them one day, she was horrified by their quality, later pronouncing them 'ghastly, absolutely third-rate.'" Well, what else could they be?