Meryle Secrest's life of Berenson is twice undone by Ernest Samuels' biography, which appeared earlier this year (p. 249); for, though Samuels covers only the first half of Berenson's life, it is the more interesting, lesser known half, and he does it at least twice as well. Moreover, his thoroughness and assiduousness--he had access to the Berenson archives, which Secrest did not--make it easier than it might have been to spot her many, gross errors. The book is crudely conceived and structured around Berenson's concealment of his lowly Jewish origins and the presumed ensuing guilt; but Secrest distorts his conversion to Christianity at the outset by placing it at age 15 rather than at 20, when he was a Harvard genius and a protege of the celebrated minister Phillips Brooks. A second crucial distortion occurs when she quotes out of context a passage from Berenson's youthful article on ""Contemporary Jewish Fiction"" to make him sound blatantly anti-Semitic--whereas other passages reveal that, alienated as he might personally be, he was not without appreciation of Jewishness or of his chosen subject, Yiddish literature. Then there are the ridiculous ""facts,"" as per Secrest's celebration of Florence, ""which, until King Victor Emmanuel moved his court to Rome, in 1879,. had been the capital of Italy""--but merely for the five years since the country's unification. And there is, finally, her apparently total igonorance of art, as when she questions Berenson's preference for Venetian art of the Renaissance over Florentine--""which is, by general agreement, superior."" That idiocy is compounded by her incomprehension of Berenson's observation that ""they are more painters than the Florentines""--which, as art-survey students learn, means more painterly, a perfectly sound distinction. A mishmash of mistakes and misunderstanding.