Cosine tells girls how to put rouge on their breasts and Ms. tells you how to start your own business, but no one tells file clerks that life will stretch into a big zero unless they improve their skills,"" says middle-aged Mrs. Levine at a Flat-bush consciousness-raising session, and her offhand remark is representative of the fundamental subjects and sensible focus sustained throughout journalist Susan Jacoby's writings of the past several years. Not that all of the pieces (many appeared in the ""Hers"" column of the New York Times) are equally incisive: there are a few forgettable or ephemeral ones, but more often feminist Jacoby selects a central issue and pursues its main themes with clarity and discrimination. In considering the Michigan woman, battered for years, who set fire to her sleeping ex-husband--a Movement cause câ€šlebre--she insists that the unwritten law which supported her behavior is a weak substitute for a written law that would protect her. Or in regretting the scarcity of immigrant women's literature, she can value World of Our Fathers for its many achievements and yet see its deficiencies (""Howe's generic treatment of childhood on the Lower East side deals entirely with boys""). There are nuanced perceptions on teenage pregnancy, men's reliance on women as emotional outlets, the generally unreported diversity of the single life, reasons for defending the rights of pornographers (even though their work degrades women), and--though a confirmed non-parent herself--a dismayed look at ""Kid Haters"" in which she cites Urie Bronfenbrenner's suggestion that one index of a society's worth is ""the concern of one generation for the next""--an attitude echoed elsewhere in her own admiration of her grandmother. Some of these pieces, although noteworthy when first published, remain valid but no longer seem fresh--an inevitability, perhaps, but one which may deter otherwise-responsive readers; in the main, however, her subjects and no-nonsense presentation reflect a discerning sensibility.