Subtitled ""the unauthorized biography,"" Higham's latest foray into flickerdom's seamier purlieus is rife with intimations of titillating, carefully guarded secrets. But readers taken in by this unspoken promise will no doubt be let down to discover that the text is merely a largely uncritical collection of long-familiar facts. Even its subject, widely recognized as one of Hollywood's testiest, most obsessively ""uncooperative"" stars, is unlikely to find much to complain of here. The author's gentle handling of Brando's often controversial public and private lives is curious. It was Higham, after all, who stigmatized Errol Flynn as a covert homosexual and Nazi agent in Errol Ftynn: The Untold Story. Recent press announcements indicate, furthermore, that Higham is preparing an equally scandalmongering portrait of the late Cary Grant. Not that this bio is lacking in such details as Brando's compulsive womanizing, his utter disregard for what used to be called ""common decency,"" or his megalomania. It is merely that Higham seems untypically hesitant to play the shocked custodian of public morality--a role he has assumed to profitable effect in most of his previous celebrity portraits. He fails, for example, to comment on the fact that Brando's highly publicized concern for the world's oppressed never seems to have extended to the women he repeatedly used (and apparently abused) throughout his career. On the stylistic level, the writing here is no better and no worse than what Higham's readers have come to expect--slapdash but breezily confident. In the end, the reader is uncertain whether to be more offended by Brando's antics or by his biographer's slightly toadying manner in recounting them.