Mr. Lopez reinterprets the civilization of the High Renaissance in Italy as a dramatic succession of three ages: Youth, 1454-1494; Maturity, 1494-1527; Decline, 1527-1559. In the first period, political and economic stabilization brings forth a mood of confident expectation which expresses itself in literature, art, and philosophy, all reaching for a goal of ''self-centered aesthetic harmony.'' In the second period, a series of foreign invasions shatters the political and economic well-being of the Indian elite but does not slow down the artistic and literary drive. Whether in hope or in sorrow, in response to shock or in escape from reality, the Renaissance attains its glorious climax. The third period is torn between conflicting tendencies. The political battle is lost but there is a second economic revival; art and literature give out despondent notes but successfully explore new channels; philosophic permissiveness comes to an end but scientific reserach comes into its own. Mr. Lopez's tripartition of an age which is usually described as a single sweep adds depth to the definition of the Italian Renaissance. It is enhanced by his fresh translations of Renaissance poems and by twenty-four illustrations which pick out from the incomparable wealth of Renaissance art a few historically significant works. All the famous names are there, from Lorenzo de'Medici to Ariosto, Machiavelli, and Cardano, from Botticelli to Leonardo, Michelangelo, and Palladio; but one also meets a large number of minor figures and anonymous people in the street. America is discovered; new diseases appear; anti-Semitism reawakens; religious unity is destroyed - these and other events form the backdrop. The sparkling narration is thoroughly grounded in contemporary sources.