When the great founder of Italian art visited Siena in 1266 for the completion of his pulpit in the Duomo, he found a guild of sculptors, or _taglia-pietri_, in that city, numbering some sixty members, and governed by a rector and three chamberlains. Instead of regarding Niccola with jealousy, these craftsmen only sought to learn his method. Accordingly it seems that a new impulse was given to sculpture in Siena; and famous workmen arose who combined this art with that of building. The chief of these was Lorenzo Maitani, who died in 1330, having designed and carried to completion the Duomo of Orvieto during his lifetime.[67] While engaged in this great undertaking, Maitani directed a body of architects, stone-carvers, bronze-founders, mosaists, and painters, gathered together into a guild from the chief cities of Tuscany. It cannot be proved that any of the Pisani, properly so called, were among their number. Lacking evidence to the contrary, we must give to Maitani, the master-spirit of the company, full credit for the sculpture carried out in obedience to his general plan. As the church of S. Francis at Assisi formed an epoch in the history of painting, by concentrating the genius of Giotto on a series of masterpieces, so the Duomo of Orvieto, by giving free scope to the school of Pisa, marked a point in the history of sculpture. It would be difficult to find elsewhere even separate works of greater force and beauty belonging to this, the first or architectural, period of Italian sculpture; and nowhere has the whole body of Christian belief been set forth with method more earnest and with vigour more sustained.[68] The subjects selected by these unknown craftsmen for illustration in marble, are in many instances the same as those afterwards painted in fresco by Michael Angelo and Raphael at Borne. Their treatment, for example, of the creation of Adam and Eve, adopted in all probability from still earlier and ruder workmen, after being refined by the improvements of successive generations, may still be observed in the triumphs of the Sistine Chapel and the Loggie.[69] It was the practice of Italian artists not to seek originality by diverging from the traditional modes of presentation, but to prove their mastery by rendering these as perfect and effective as the maturity of art could make them. For the Italians, as before them for the Greeks, plagiarism was a word unknown, in all cases where it was possible to improve upon the invention of less fortunate predecessors. The student of art may, therefore, now enjoy the pleasure of tracing sculpturesque or pictorial motives from their genesis in some rude fragment to their final development in the master-works of a Lionardo or a Raphael, where scientific grouping of figures, higher idealisation of style, the suggestion of freer movement, and more varied dramatic expression yield at last the full flower that the simple germ enfolded.