William Blake grew up in modest circumstances in London in the late 18th century. He had little formal schooling but became a skilled engraver and artist. Blake was a poet, painter, and printmaker who produced works that combined imagination and mysticism. Some of his most famous poems include "The Tyger," "A Poison Tree," and "The Sick Rose." While he had a complex relationship with Enlightenment philosophy, rejecting rationalism and empiricism, his works blended reason and emotion. Blake believed "in the universe there are things that are known and things that are unknown and in between there are doors."