Sociologist Sennett (The Fall of Public Man, Authority) ventures, uncertainly, into fiction--with a book that purports to be the collected personal papers of a Hungarian intellectual named Tibor Grau (seemingly based, at least in part, on Georg Lukacs). These papers detail, mostly through indirection, Grau's constantly uneasy but always surviving position vis à vis state power: to Grau, ""a face without a mask gets frostbitten from the cold""; after all, as the homosexual son of a prominent Jewish banker of Budapest, he has become accustomed to degrees of masquerade. And the book's most effective section presents Grau as a functionary in Bela Kun's short-lived Hungarian Soviet of 1919: he doctors a poem (rendering it ridiculous) to fit propaganda purposes; he watches the same basic revisionism allow a murder to be pinned unjustly on a friend; he wholeheartedly attempts to alter fairy tales. (The title's thematic allusion: a frog who is himself cannot help but croak.) Does Tibor eventually ""croak,"" then--by speaking out as a free and a different man? Well, yes and no--which is presumably Sennett's modulated point. Yet the book's intellectual texture and pattern is a hindrance here: the effect is consciously self-contained and patchy--with more emphasis on carpentered paradigms than On the painful inconsistency of a full, individual life. (Tibor's sexuality, for instance, is all but totally tangential.) Thoughtful intentions, then--and socio-historical interest--but very limited appeal as fiction.