 But these are all composite concepts; they all involve putting two quite different notions together: ‘highest’ with ‘good’, ‘first’ with ‘cause’, and so on. Scotus says that we can come up with a relatively simple concept that is proper to God alone, the concept of “infinite being.” Now that concept might seem to be every bit as composite as “highest good” or “first cause,” but it’s really not. For “infinite being” is a concept of something essentially one: a being that has infinity (unlimitedness) as its intrinsic way of existing. I will return to the crucial role of the concept of infinite being in Scotus’s natural theology after I examine his proof of the existence of God.