Richard Gilman is a bold, flashy, impassioned critic, rather like a maverick politician who, knowing he'll never be elected, presents himself as an exhilarating witness to the truth. Alas, he works in an even trashier arena, that of the theatre, so his collection of reviews, originally aired in such places as Commonweal and Newsweek over the last ten or twelve years, seems, more often than not, an odd milieu for his sort of rhetoric or presumed moral fervor. Gilman covers a wide spectrum, including, in his better moments, the lights of the present (Albee, Pinter, Williams, Miller, Beckett, Ionesco), as well as the beacons of the past (Brecht, O'Neill, Pirandello, Ibsen). But, by and large, his insistent ""truth-saying,"" which generally represents the consensus of New York intellectual opinion at any given time, lacks the authenticity and probity which would make such a stance palatable, both in feeling and ideas. Remarking on Gilman recently, Philip Rahv found him ""full of profuse and idle talk,"" and thought that ""the inveterate journalist shows through the aesthetic mask all too often."" In 1964, he was not particularly impressed by the sensuosity of Marat/Sade; today he appears to favor it. Fashions change, and Gilman catches up. Now and again one is delighted by the sparkle and force of his observations. The lasting impression, however, is ephemera unredeemed by polemics, and a rather grating style.