They began together, as Marx-fired schoolteachers ""running across still dewy meadows to reach their secret rendezvous,"" and they're together again now, she the ""revered grandmother of a triumphant sisterhood"" (via Second Sex), he the blind, embattled eminence. But the author of this odd amalgam--parallel biography (paraphrasing, quoting from the Memoirs), uncritical literary criticism, Intro to Philosophy & Politics--fails to capture the ""certain fidelity"" of ""Sartre and Beaver"" that has distinguished their 50 years as lovers, lovers of others, mutual literary mentors, and ""apolitical"" comrades in arms, protests, or print. Aside from a stray dollop of lyrical goo (""Sartre and Beauvoir are exegesis made passion""), Madsen gives up on treating them together early on and resigns himself to following one or the other from book to book, cause to cause, and lover to lover. And his style adapts rather too easily to each change of venue: omniscient-narrator for romance (""The moment she looked [lover Nelson] Algren in the eyes, she felt she had been right in coming back""), jargon-y for, quick looks at phenomenology or structuralism, slightly heated for Sartre's ideological skirmishes with enemies to both left and right. Further fragmenting the divided canvas is the weird notion of beginning each chapter with a leap forward in time, then flashing back to fill in. Some involvements--like de Beauvoir's fury over Algerian atrocities--develop into striking set-pieces, but, with two heavily documented lives to cover, Madsen can do little more than summarize and simplify--with what seems to be a dilettantish dispatch. Which might be forgivable. . . if only the couple at the center ever came to life.