This point is so important for its bearing on Renaissance art that I may be permitted to dilate at greater length on Signorelli’s choice of types and treatment of form in general.  Having a special predilection for the human body, he by no means confined himself to monotony in its presentation.  On the contrary, we can trace many distinct grades of corporeal expression.  First comes the abstract nude, illustrated by the “Resurrection” and the arabesques at Orvieto[212].  Contemporary life, with all its pomp of costume and insolence of ruffling youth, is depicted in the “Fulminati” at Orvieto and in the “Soldiers of Totila” at Monte Oliveto[213].  These transcripts from the courts of princes and camps of condottieri are invaluable as portraits of the lawless young men who filled Italy with the noise of their feuds and the violence of their adventures.  They illustrate Matarazzo’s Perugian chronicle better than any other Renaissance pictures; for in frescoes like those of Pinturicchio at Siena the same qualities are softened to suit the painter’s predetermined harmony, whereas Signorelli rejoices in their pure untempered character[214].  These, then, form a second stage.  Third in degree we find the type of highly idealised adolescence reserved by Signorelli for his angels.  All his science and his sympathy with real life are here subordinated to poetic feeling.  It is a mistake to say that these angels are the young men of Umbria whom he loved to paint in their striped jackets, with the addition of wings to their shoulders.  The radiant beings who tune their citherns on the clouds of Paradise, or scatter roses for elect souls, could not live and breathe in the fiery atmosphere of sensuous passions to which the Baglioni were habituated.  A grave and solemn sense of beauty animates these fair male beings, clothed in voluminous drapery, with youthful faces and still earnest eyes.  Their melody, like that of Milton, is severe.  Nor are Signorelli’s angelic beings of one uniform type like the angels of Fra Angelico.  The athletic cherubs of the “Resurrection,” breathing their whole strength into the trumpets that awake the dead; the mailed and winged warriors, keeping guard above the pit of “Hell,” that none may break their prison-bars among the damned; the lute-players of “Paradise,” with their almost feminine sobriety of movement; the flame-breathing seraphs of the day of doom; the “Gabriel” of Volterra, in whom strength is translated into swiftness:—­these are the heralds, sentinels, musicians, executioners, and messengers of the celestial court; and each class is distinguished by appropriate physical characteristics.  At the other end of the scale, forming a fourth grade, we may mention the depraved types of humanity chosen for his demons—­those greenish, reddish, ochreish fiends of the “Inferno,” whom Signorelli created by exaggerating the more grotesque qualities of the nude developed in his arabesques.  We thus obtain four several degrees of form:  the demoniac, the abstract nude, the adolescent beauty of young men copied from choice models, and the angelic.