Biographers are beholden to the kindness of strangers. Contemporary biographers have to work on cultivating their sources. Like brokers, biographers make cold calls, soliciting business. Even a biographer like Laurence Leamer, with biographies of the Kennedys and the Reagans under his belt, starts a new biography from zero. Whoever he has already cultivated will no doubt assist him on his new project, but to his new, living subject, he is nevertheless a newcomer.

So the first thing the biographer is eager to broadcast in “Fantastic: The Life of Arnold Schwarzenegger” (St. Martin’s Press, 432 pages, $24.95) is that Arnold Schwarzenegger “allowed me several interviews. He answered every question that I asked him.” Ah, my skeptical biographer’s sensibility wonders, “But what questions did you ask?” And then there is the governor’s wife: “Maria Shriver also gave me an interview, and I would like to thank her too.” Only one?

What price access? As soon as a biographer rubs up against his subject, the biography changes. Mr. Schwarzenegger, one of the consummate geniuses of public relations, knows this well. Indeed, he has collaborated on other books about himself and has masterfully controlled his image – a word that he finds no shame in using, since he believes that his clout derives as much from the way press shapes perceptions of him as any actual muscle he can flex.

For an Arnold Schwarzenegger, a biography holds no terrors; it is just another competitive contest he is determined to win. To Arnold, that Mr. Leamer has written biographies of the Reagans and Kennedys and wants to do Arnold only means that he has arrived.

So is Mr. Leamer a Schwarzenegger lackey? He veers in that direction with his fulsome tributes to the governor’s staff. But then up front he announces that his subject “neither sought nor received any special consideration … and this is in no way an authorized book.” But I don’t mean to undermine Mr. Leamer, or imply that his biography is something short of fantastic. He has done a splendid job. I would even say his book is “fair and balanced” – if that phrase itself had not of late been appropriated for partisan purposes.

Mr. Leamer could write a book, no doubt, about the complications of doing this biography, which would give the lie to his acknowledgments. Or, to put it another way, his acknowledgments – any biographer’s acknowledgments – are at best half-truths. As long as the biographer is out there in the field, anticipating future projects, he is not going to come clean about the messy side of biography. To do so would seem ungrateful – or, as one source said to me when I told something he thought should be kept secret – an “abuse of hospitality.”

The Arnold Schwarzenegger who emerges from this biography is a complex subject – unusually candid for a public figure (admitting, for example, that he groped women) but always a politician, since he softened his confession by adding that his bad behavior occurred on “rowdy movie sets.” It was Hollywood, you see, not me! The honest biographer points out, however, that a good deal of the groping occurred nowhere near filmland.

But though the biographer is graphic, and even includes a scene in which his subject power-lifts a female photographer by her crotch in an elevator, he does not dwell on Arnold’s penchant for sexual harassment. Mr. Leamer is more concerned with political genius – a gift that manifested itself very early in Mr. Schwarzenegger. Mr. Schwarzenegger went AWOL from the Austrian army, for example, to win his first bodybuilding championship. He was punished with a week in the brig and then touted by his commanding officers for showing the initiative they wanted inculcated in their other soldiers.

Arnold was famous for psyching out his rivals. Men with bodies equal to his crumbled when competing with him. In one instance, he claims, he won a title by suggesting the men pose against a dark wall in a warm-up room. Arnold’s white contours outshone his darker-skinned opponent’s formidable physique. Mr. Leamer points out that Mr. Schwarzenegger himself thought he was overweight and even said afterwards that the other man should have won. But that is exactly the Schwarzenegger strategy: Play mind games with your opposition, win, and then not only portray yourself as a generous victor but suggest that your triumph was a matter of tactics, not of innate superiority. Mr. Schwarzenegger has always sought to present himself as the great persuader.

Which brings us to Hitler. There is no doubt that the young Schwarzenegger was an extravagant admirer of Herr Schickelgruber (the family name Hitler’s father abandoned). Arnold admired Hitler’s mesmerizing oratory and his ability to stir the masses. Mr. Leamer finds no evidence whatsoever of anti-Semitism in Mr. Schwarzenegger, though his father was a Nazi party member and even joined the S.A. Such matters were not discussed in the Schwarzenegger household. Until Mr. Schwarzenegger planned to run for the California governorship, he did not seek to learn the truth about a father who abused him and who he never liked.

Although a streak of Austrian authoritarianism remains in Mr. Schwarzenegger, of more importance are parallels with Reagan. Like Reagan Mr. Schwarzenegger had come to the end of his movie career. He could have gone on, but the returns for his action-hero films were diminishing, and he was headed toward 60 anyway. Like Reagan, Mr. Schwarzenegger’s interest in politics was long-standing (he began talking about running for governor in the 1980s). He was not as well read or well-rounded in political philosophy as Reagan, but one of Mr. Schwarzenegger’s speechwriters, an old Reagan hand, describes his new boss as “Reagan with a different cadence.”

Mr. Leamer has no choice but to end his biography rather lamely, since it is too early to tell what legacy Governor Schwarzenegger will leave: “If Arnold fails, it will not be for want of daring greatly.”