Brief excerpts from William Blake's biography:

As a child, Blake viewed the world in the light of what Wordsworth, in his Ode: Intimations of Immortality, would later call a “visionary gleam.” When he was about nine, he told his parents he had seen “a tree filled with angels” on one of his walks; he later reported a similar vision of “angelic figures walking” in a field among workers as they gathered in the hay. Unlike the child in Wordsworth’s poem, however, Blake never outgrew these visions. He was past fifty when he described seeing the rising sun as “an Innumerable company of the Heavenly host crying Holy Holy Holy is the Lord God Almighty”.

Besides plaster casts, the young Blake also began to collect inexpensive prints from shops and auctions. His taste ran to Raphael, Michelangelo, Giulio Romano, Albrecht Dürer, and Maerten Heemskerck, artists whose work was not widely appreciated at the time. He never wavered in his conviction that they were superior to the more fashionable painters of the Venetian and Flemish schools. In the catalogue for an exhibition of his own work in 1809, he accuses artists “who endeavour to raise up a style against Rafael, Mich. Angelo, and the Antique” of attempting to destroy art.

Even as a student, Blake followed his own taste in art. When the elderly George Moser, Keeper of the Royal Academy, advised him to study Lebrun and Rubens instead of the “stiff” and “unfinished” works of Raphael and Michelangelo, the young Blake balked: “These things that you call Finishd are not Even Begun,” he later reported himself as having replied; “how can they then, be Finishd?”