Blake's reading had effected an invaluable service for him--it peopled his world of imagination. There was terror in his first approach on the threshold, a terror never forgotten and often reproduced in his designs. But when he was pushed beyond the threshold and its covering shadow, he gradually grew accustomed to the changed lights, and he began to discern its forms and its outlines and its colours. These in their turn reacted on the outer world until he saw it not as a hard unsurpassable fact, but a mirror of the inner things which in reality were the substance, the form, and the foundation. Henceforth he valued the forms and outlines of things because they were a sign and pledge to him of the inner resplendent City which was not only built on an eternal foundation but was actually the home of his spirit. As soon as he apprehended the significance of outline he developed an ardent desire to draw.
This impulse was quickly observed by his father and encouraged by him. William was sent to learn drawing from a Mr Pars, who kept a drawing-school in the Strand. Here he copied plaster casts and odd-and-end plaster bits of the human body, the body itself being left severely alone. A certain amount of technical facility was thus acquired, but his education in art advanced more surely from his desultory wanderings in sale-rooms and in the private galleries of munificent noblemen. At the sale-rooms he bought prints often for a few pence, and his little store of prints was added to by gifts from his father, who also presented him with models of the Gladiator, Hercules, Venus of Medici. In this way he gained his first enthusiastic knowledge of Raphael, Michael Angelo, Martin Hemskerck, Albert Dürer and Julio Romano, who were exactly the right teachers for him. Michael Angelo and the Florentine School believed that drawing was the foundation of all great art. Albert Dürer and his great German successors were of the same opinion. William Blake, the little citizen of the heavenly Jerusalem, had known the horror of indefiniteness, and worked through his apprenticeship to joy only when he discovered that the blessed City stood four-square, and was bounded by great walls on its four sides. Hence his selection of prints was instinctive. He knew without being told what helped him to find himself, and he escaped once for all, while still a child, the seductive elegance of his own age.