The spirits of Hell seem borrowed from grotesque bas-reliefs of the Pisan school.

The draped, winged, and armed angels of Heaven are posed with a ceremonious research of suavity or grandeur.

These and other features of his work carry us back to the period of Giotto and Niccolo Pisano.

But the true force of the man, what made him a commanding master of the middle period, what distinguished him from all his fellows of the _quattrocento_, is the passionate delight he took in pure humanity--the nude, the body studied under all its aspects and with no repugnance for its coarseness--man in his crudity made the sole sufficient object for figurative art, anatomy regarded as the crowning and supreme end of scientific exploration.

It is this in his work which carries us on toward the next age, and justifies our calling Luca "the morning-star of Michelangelo." It would be wrong to ascribe too much to the immediate influence of the elder over the younger artist--at any rate in so far as the frescoes of the Chapel of S.Brizio may have determined the creation of the Sistine.