Some method may be introduced by sketching briefly at the outset the principal periods through which the humanistic movement passed. Though to a certain extent arbitrary, these periods mark distinct moments in an evolution uniform in spite of its complexity. The first, starting with Petrarch, and including the lives and labours of those men he personally influenced, has been traced in a preceding chapter. This was the age of inspiration and discovery, when the enthusiasm for antiquity was generated and the remnants of the classics were accumulated. The second may be described as the age of arrangement and translation. The first great libraries were founded in this period; the study of Greek was pursued in earnest, and the Greek authors were rendered into Latin. Round Cosimo de' Medici at Florence, Alfonso the Magnanimous at Naples, and Nicholas V. in Rome the leaders of the Renaissance at this time converge. The third is the age of academies. The literary republic, formed during the first and second periods, now gathers into coteries, whereof the Platonic Academy at Florence, that of Pontanus at Naples, that of Pomponius Lætus in Rome, and that of Aldus Manutius at Venice are the most important. Scholarship begins to exhibit a marked improvement in all that concerns style and taste. At the same time Italian erudition reaches its maximum in Poliziano. Externally this third period is distinguished by the rapid spread of printing and the consequent downfall of the humanists as a class. In the fourth period we notice a gradual decline of learning; æsthetic and stylistic scholarship begins to claim exclusive attention. This is the age of the purists, over whom Bembo exercises the sway of a dictator, while the Court of Leo X. furnishes the most brilliant assemblage of literati in Europe. Erudition, properly so called, is now upon the point of being transplanted beyond the Alps, and the Revival of Learning closes for the historian of Italy.