  Principles are “self-evident” (cf. Aristotle, Topics, 100a31–b21).  In the second of Aristotle’s modes of per se (Aristotle, Posterior Analytics 73a34–b3), the essence of the subject causes the predicate. This provided Bonaventure with an ingenious explanation of why principles are self-evident: “We know principles to the extent that we understand the terms which make them up, because the cause of the predicate is included in the subject.” If the essence of the subject term is what connects it to the predicate term in a self-evident proposition, then the essence of God must be what makes “God exists” self-evident. The positive ontological argument contains an inference to the existence of God that runs through the divine essence.