By now, collections of Columbia University philosopher Danto's review-essays on contemporary art are familiar; this fifth installment again centers on work reprinted from his regular column in the Nation, where he has been art critic since 1984. Danto may be one of the few critics whose work reads better in book form than as a journalistic review. His critical judgments are often less ends in themselves than jumping off points for explorations of particularly vexing problems in aesthetics, threaded through with references to art and philosophy classics, all of it undertaken in clear language and with an even, appreciative tone. In these 40-plus pieces, each of which is six to eight pages long, Danto covers younger artists like John Currin and Renee Cox; older living masters like Gerhard Richter and Sol LeWitt; New York School artists like Philip Guston and Joan Mitchell, whose reputations are still settling; and Modernist masters like Malevich, Giacometti and Picasso. Given an art scene and museum world driven to a great extent by power, glitz and internecine politics, Danto's reflective approach can be a welcome respite for insiders and a friendly introduction to aesthetics as it continues to play out in real time. Agent, George Borchardt.