In this sixth collection of his syndicated "On Language" columns, Safire deals wittily, playfully and, above all, instructively with thorny linguistic issues. He takes to task writers who use the passive voice, elitists who grimly stick to "dicta" and "memoranda" despite the general preference for "-ums," and groups who declare themselves offended by the use of certain words (such as "tribes"). The lordly language maven discusses the proper use of "his/hers/theirs," the pronunciation of "vagaries," the naming of pets and perfumes, the difficulty of pinning down a definition of "secular humanism." As in previous collections, Safire includes articulate and ornery responses from the Gotcha! Gang, the Nitpickers League, and such individuals as Jacques Barzun, Daniel Moynihan and Art Buchwald.