One of the great English Romantic poets, William Blake was also an artist, mystic, and visionary. His work ranges from the deceptively simple and lyrical Songs of Innocence and their counterpoint Experience--which juxtapose poems such as "The Lamb" and "The Tyger," and "The Blossom" and "The Sick Rose"--to highly elaborate, apocalyptic works, such as The Four Zoas, Milton and Jerusalem. Throughout his life Blake drew on a rich heritage of philosophy,...