Revealed Christian tradition suggests similarity of a certain kind between the transcendent God and his creatures. “Let us make man in our image, after our likeness,” says the book of Genesis. The Catechism of the Catholic Church is even more detailed: “Created in the image of the one God and equally endowed with rational souls, all men have the same nature and the same origin.” This principle—formally named the imago dei, or image of God, doctrine—informs much of Western theism, whether Christian or Jewish or Islamic. So commonplace is it in the philosophical and theological tradition that it is often taken for granted. Still, there was a time when it was not. St Augustine’s work may be reckoned a stark example; the Christian Trinity—Father, Son, and Holy Spirit—is reflected in the tripartite mental psychology of human souls. Others, building on Augustine’s inspiration, labor toward securing a rational ground for the revealed dogma in other areas of their metaphysics; St Thomas Aquinas is a paradigm instance. But it should be appreciated that the tradition is carried further into the modern period, a period celebrated (notorious?) for having cast to one side the ill-considered views of their backward scholastic predecessors. It should come as no surprise that Leibniz, eclectic philosopher par excellence, respectful of his forebears and eager to utilize whatever “gold” he could uncover in that old scholastic “dross,” would prize a doctrine both mysteriously theological and intimately philosophical.