 Although metaphysics cannot surpass the limits of human knowledge, Marsilius considered it to be the entry point to theology. Natural reason is capable of forming some adequate and true concepts of God, and also of forming true propositions about God. It is able to prove that God exists and possesses knowledge and will. But it cannot demonstrate that God has free will or infinite power. This, Marsilius claimed, was also true for philosophers such as Aristotle, whose teachings equal those of natural reason  itself.[23]