Has Louis B. Mayer been unfairly portrayed--as a crass, dumb Big Mogul--by Bosley Crowther (Hollywood Rajah, 1960) and other Hollywood-watchers? So Carey says. But though this undistinguished, mostly readable bio omits apocryphal anti-Mayer anecdotes and offers some alternative interpretations, it never introduces the sort of new data needed for convincing ""revisionist"" film-history. Son of immigrants who wound up in St. John, New Brunswick, ambitious Louis traveled in metal-trading, married in Boston, became intrigued with show-biz commerce, leased a theater in Haverhill. . . and gradually moved into distribution (making a killing on Birth of a Nation) and then small-scale production. The move to Hollywood soon followed, and thereafter--from the 1924 Metro-Goldwyn merger onward, the book is pretty much the familiar, star-studded MGM story, except when Carey attempts to brush up Mayer's image. ""He was not so much anti-director as procollaboration."" Yes, Stroheim's Greed was ravaged by Mayer and Thalberg, but ""the release version . . . is perfectly logical and extraordinarily powerful."" Mayer's dabbling in conservative politics wasn't motivated only by narcissistic ambition but also by a desire to increase the film industry's prestige. There is ""no concrete evidence"" that anyone at MGM tried to sabotage John Gilbert's career. Mayer, though occasionally unfaithful to his invalid wife, didn't sleep with MGM stars, He was sincere in his stifling paternalism toward actors. Etc. The least convincing defense? MGM's treatment of Judy Garland (pills, Mayer's opposition to psychotherapy) is feebly explained. The most important argument? That Thalberg has been idealized, that mogul Nicholas Schenck was largely to blame for Thalberg/Mayer tension, that MGM quality didn't decline after Thalberg's death, that Mayer was a great showman--an equal collaborator in the great MGM productions. Most of this is plausible, but not proven; and Mayer never becomes a three-dimensional personality here. But if the reassessment of Mayer seems mostly just a passable excuse for a fairly likable recycling of Hollywood history (the Lunts' ""no lips"" anecdote yet again!), movie buffs probably won't mind much at all.