Montgomery Clift's short, sad life--or an unreasonable facsimile thereof--is now a sad, bad book. Sad, because so many of the actor's friends and lovers seem to have been willing (naivetÃ‰ revenge for old hurts?) to contribute horror-story examples and amateur analyses of Clift's miseries and madnesses. Bad, because LaGuardia has heaped up the gossip, changed a few names, added his own pseudo-Freudianisms, and churned it all out chronologically in sub-literate, hysterical screen-magazine prose. Monty's ""titanic need to relive the mother-loving of his formative years"" made sex a problem, so the ""incredibly beautiful"" ""carefree young Apollo would soon be haunted by demons"": older women, boys, liquor and pills in ""unbelievable proportions."" (""And he drinks. . . and he drinks."") No matter that the bobby-soxers' idol was the pre-Brando harbinger of the postwar ""new macho"" (?), or that he was ""unbelievably brilliant"" in films from Red River to From Here to Eternity to Suddenly Last Summer and ""acted with tactility"" on the stage; guilt over his bisexuality--or, gee, maybe it was hebephrenia--made him a ""superchild"" who fed on raw meat and baby food, hurled obscenities at guests, ate off other people's plates, passed out nightly, crashed his car, ruined his looks, made a lousy lover, and became uninsurable and unusable as an actor. Film fans who revel in disillusionment will surely lap up the cesspool of detail and the glimpses of Liz, Marilyn (they were sweet to Monty), and John Huston (he drove him over the edge while directing Freud). Yes, ""Now the demons would start to visibly rip Monty apart,"" and infinitive-splitting, dreck-splattering LaGuardia is the first.