It will be felt by every genuine student of art that if Orcagna painted these frescoes in S. Maria Novella, whereof there is no doubt, he could not have executed the wall-paintings in the Campo Santo at Pisa attributed to him by Vasari.  To what artists or artist we owe those three grave and awful panels, may still be regarded an open question.[130] At the end of the southern wall of the cemetery, exposed to a cold and equal north light from the cloister windows, these great compositions, after the lapse of five centuries, bring us face to face with the most earnest thoughts of mediaeval Christianity.  Their main purpose seems to be to illustrate the advantage of the ascetic over the secular mode of life, and to school men into living with the fear of death before their eyes.  The first displays the solitary vigils, self-imposed penances, cruel temptations, firm endurance, and beatific visions of the anchorites in the Thebaid.  The second is devoted to the triumph of Death over the pomp, strength, wealth, and beauty of the world.  The third reveals a grimly realistic and yet awfully imaginative vision of judgment, such as it has rarely been granted to a painter to conceive.  Thus to the awakening soul of the Italians, on the threshold of the modern era, with the sonnets of Petrarch and the stories of Boccaccio sounding in their memories, this terrible master presented the three saddest phantoms of the Middle Ages—­the spectre of death omnipotent, the solitude of the desert as the only refuge from a sinful and doomed world, the dread of Divine justice inexorable and inevitable.  In those piles of the promiscuous and abandoned dead, those fiends and angels poised in mid-air struggling for souls, those blind and mutilated beggars vainly besieging Death with prayers and imprecations for deliverance, while she descends in her robe of woven wire to mow down with her scythe the knights and ladies in their garden of delight; again in those horses snuffing at the open graves, those countesses and princes face to face with skeletons, those serpents coiling round the flesh of what was once fair youth or maid, those multitudes of guilty men and women trembling beneath the trump of the archangel—­tearing their cheeks, their hair, their breasts in agony, because they see Hell through the prison-bars, and hear the raging of its fiends, and feel the clasp upon their wrists and ankles of clawed hairy demon hands; in all this terrific amalgamation of sinister and tragic ideas, vividly presented, full of coarse dramatic power, and intensified by faith in their material reality, the Lorenzetti brethren, if theirs be indeed the hands that painted here, summed up the nightmares of the Middle Age and bequeathed an ever memorable picture of its desolate preoccupations to the rising world.  They have called to their aid poetry, and history, and legend.  Boccaccio supplies them with the garden scene of youths and damsels dancing among roses, while the plague is at their gates, and death is in