For over thirty years, Bill Viola has created single-channel videos as well as sound and video installations that focus on spirituality and explore multiple levels of human consciousness. In constructing these works, the artist draws from his extensive study of Eastern and Western art, philosophy, and religion. He also consistently deploys cutting-edge technologies, investigating new ways to manipulate viewers’ percep-tion. Both the videos in The Reflecting Pool and the installation Reasons for Knocking at an Empty House are important early works that foreshadow Viola’s later creations, combining philosophic inquiry with captivating physical environments.