Delivered over the course of 1891 and 1893, George Gabriel Stokes's Gifford Lectures focused on the question of Divine Design, which he defined as God's Will and creation itself. Stokes contrasts Design with materialism, which posits that all life and all inorganic phenomena are caused by natural laws, and nothing more. Stokes rebuts that view by arguing a materialistic conception of the universe cannot explain why certain natural laws exist, such as the law of gravitation. It can only describe the phenomena we observe in the form of mathematical theories.