One evening a lad, scarcely more than a child, knocked at his door and was coldly received, being suspected of mere idle curiosity. But short conversation with the young Leonardo—for it was he—convinced the astronomer, as before it had convinced Biagio da Ravenna, of his wonderful aptitude for mathematics. Ser Paola became his teacher; on summer nights they went together to Poggio del Pino, one of those fragrant, pine-clad, heather-carpeted hills, girdling the City of Flowers; there Toscanelli had built his observatory. He taught the boy all he himself knew of the laws of the universe. It was from these lessons that Leonardo dated his faith in the experimental study of nature, as yet too much neglected by the philosophers.
Ser Piero da Vinci, though he put no difficulties in the way of his son's studies, advised him to choose some more lucrative occupation; having noticed his bent towards modelling and drawing, he showed some of the boy's work to Andrea Verrocchio, the painter and goldsmith; and shortly afterwards Leonardo was formally entered as one of this artist's pupils.
VIII
Verrocchio, the son of a poor furnace-stoker, was seventeen years the senior of Leonardo. His face was placid, flat, and pale, with a double chin. Only in his tight shut lips and piercing eyes was there evidence of singular intelligence. Spectacles on nose, magnifier in hand, he sat in his dark bottega near the Ponte Vecchio, looking more like a small shopkeeper than a great artist. A disciple of Paolo Uccello, he, like his master, affirmed that Perspective must be based on science. 'Geometry,' he said, 'being a part of mathematics, mother of all knowledge, is also the mother of drawing, which is the father of all the arts.' Complete knowledge and complete enjoyment of beauty were to him identical. Unlike Botticelli, and others of his kidney, Verrocchio was neither ravished by extraordinary beauty nor repelled by unusual deformity. In both he found occasion for study. He was also the first master who made anatomical models. If Botticelli had found the fascination of art in the miraculous, in the fabulous, in that mystic haze which confounds Olympus with Golgotha—for Verrocchio it lay in patient investigation and a firm grasp of the verities of nature. The miraculous was not true for him. Truth was the miracle.
This was the man to whom Ser Piero brought his seventeen-year-old son; he became Leonardo's teacher; further, he became his disciple. The monks of Vallombrosa had commissioned Ser Andrea to paint them a Baptism of Christ, and the master set his pupil to execute the kneeling angel which formed part of the composition. The result showed Verrocchio that his scholar knew intuitively and clearly all that he himself had dimly guessed and sought for gropingly, slowly and laboriously, through a fog.
Later it was said that Verrocchio gave up painting because jealous of the young man's superiority; in reality there was never anything but harmony between the two. Each supplied the deficiency of the other. The pupil had lightness and precision of touch; Verrocchio, perseverance and concentrated attention. They worked together without envy, without rivalry, scarce knowing how much they owed each other.
At that time Verrocchio executed the bronze group for Orsanmichele, which was known as the 'Incredulity of St. Thomas.' It was altogether unlike the celestial dreams of the Beato Angelico or the delirious idealism of Sandro Botticelli. In St. Thomas's mysterious smile, as he put his fingers into the print of the nails, was exhibited for the first time the boldness of man before his God; Reason face to face with Miracle.