In the progress of intelligence, the fifteenth century constitutes a splendid era. Advances were then accomplished in moral, intellectual, and political knowledge, which form the ground work of no inconsiderable portion of modern science. In the arts of elegance, especially in sculpture, the labours of this age will always hold distinguished rank. In the first year of the century, we find six great masters--competitors for the same public work--the bronze folding-doors of the baptistry at Florence: Brunelleschi and Ghiberti, Florentines; Jacomo della Quercia of Sienna; Nicolo Lamberti of Arezzo; Francisco di Valdambrino, and Simon dei Colle, Tuscans. The competitors each afterwards became the head of a flourishing school. Ghiberti, a youth of twentythree, was the successful candidate; and the work thus assigned to his superior merit, occupied forty years of his future life, remaining still one of the proudest triumphs of modern talent. The subjects are upon panels in relievo, representing historical passages from the Old and New Testaments, and the same which were afterwards declared worthy the gates of Paradise. This era may be styled the commonwealth of sculpture; no single master so far excelling his compeers as to impress upon the art the stamp and bearing of one individual style. But among this crowd of illustrious contemporaries, Donatello, born in 1383, and already an eminent artist at the age of twenty, stands forth pre-eminently conspicuous by the magnitude and excellence of his own labours, as also by the number and merits of his pupils. His performances, in almost every variety of material, are scattered over all Italy; the best are in Florence, but the equestrian statue of Erasmus, Duke of Narni, in that city, merits attention as the first attempt of such magnitude in the revival of art. The numerous scholars of Donatello may be divided into two classes. The first comprehends those who, without producing much of their own, have attained reputation as fellow-labourers in the most considerable undertakings of their master. The legitimate disciples of Donatello, however, consists of those who, without servilely following in the train of their instructer, preserved, or even in some respects improved, the science derived from his precepts. These include most of the leading masters of the latter part of the century, for in every town of importance he had left works and planted a school. After the demise of Ghiberti in 1455, and of Donatello in 1466, the art was far from languishing in the hands of their successors, and especially under Andrea du Verrochio, towards the close of the century. In the academy founded by the Medici, many of the most eminent men of the next century are to be found, as yet youthful though not undistinguished pupils.