fundamentum divisionis (Latin ‘foundation of a division’), term in Scholastic logic and ontology meaning ‘grounds for a distinction’. Some distinctions categorize separately existing things, such as men and beasts. This is a real distinction, and the fundamentum divisionis exists in reality. Some distinctions categorize things that cannot exist separately but can be distinguished mentally, such as the difference between being a human being and having a sense of humor, or the difference between a soul and one of its powers, say, the power of thinking. A mental distinction is also called a formal distinction. Duns Scotus is well known for the idea of formalis distinctio cum fundamento ex parte rei (a formal distinction with a foundation in the thing), primarily in order to handle logical problems with the Christian concept of God. God is supposed to be absolutely simple; i.e., there can be no multiplicity of composition in him. Yet, according to traditional theology, many properties can be truly attributed to him. He is wise, good, and powerful. In order to preserve the simplicity of God, Duns Scotus claimed that the difference between wisdom, goodness, and power was only formal but still had some foundation in God’s own being. A.P.M.