A fourfold light, and yet it illuminates six degrees of human science: "There is the light of sensitive knowledge, the light of the mechanical arts, the light of rational philosophy, of natural philosophy, and of moral philosophy, and lastly, the light of grace" (Augusta Theodosia Drane, Christian Schools and Scholars, 1867). Our illustration of fourfold light appears in El Mundo Físico by A. Guillemin, 1882.