A likely story
Every year, I teach the classic theistic arguments in my philosophy of religion class. We start with the “ontological” argument in Anselm’s Proslogion. Steeped as it is in monastic and biblical prayer, the Proslogion is more like a journey toward the intellectual vision of God than it is like a chapter in a philosophy textbook; yet in a few short paragraphs, Anselm contends rather ingeniously that for God, understood as “something than which nothing greater can be thought,” nonexistence is simply not a conceivable option.
My students find Anselm wonderfully discombobulating. On the one hand, his confession, at the beginning of the Proslogion, of the parlous state of his mind and soul strikes them as pathologically self-deprecating; on the other hand, his claim to have captured “a single argument that needed nothing other than itself” to prove God’s existence seems audacious in the extreme. We moderns are used to occupying a limited middle range between self-trust and self-doubt; our confidence in reason will never soar as high as Anselm’s, while our “skepticism of the instrument” (as H. G. Wells called it) will never sink as low. Compared to Anselm, we are Caspar Milquetoast.
Thomas Aquinas, the next figure on our syllabus, is no less humble and no less daring than Anselm, though he differs with him on the best means of approach. For Thomas, philosophical demonstration of God’s existence, though a mere “preamble” to the fullness of the faith, is a healthy use of our God-given reason and can be done with confidence. Rather than a single argument, Thomas proposes a number of pathways: one may reason from effects to a logically prior first cause, from contingent beings to necessary being, from relative goods to their maximum, from final causation (or teleology) in nature to an intelligence who directs natural bodies to their proper ends, and so on. Follow any of these pathways, Thomas tells us, and though it may lead only to the outer portico of the divine mysteries, it will demonstrate with absolute certainty that God truly and necessarily exists.
