I spent some time discussing Anselm’s ontological argument for the existence of god earlier today, and something struck me. It’s neither all that profound nor original (probably), but I found it a good way to tie in the influence of ancient metaphysics to Anselm’s thinking. Put it this way: Anselm, in order to think it rational to believe that something that exists in the mind (i.e. that than which nothing greater can be conceived) can, in some sense, necessarily exist solely based on its conceptual structure must assume some variation of an “essence-precedes existence” logical paradigm, whereas if “existence-precedes-essence”, then it would be impossible to move from a single entity to its conceptual necessity. Now, where would this presupposition come from for Anselm?
In Anselm’s time, Johannes Scotus Eruigena had recently been the one to re-discover a number of Neo-Platonic texts and translate them into Latin, so there’s a sense in which this stuff is in the air. I mentioned to my student that it is possible to frame this debate as one between the battling traditions of Plato and Aristotle’s metaphysics:
Plato: Forms are primary to particular things, and it is therefore possible to think of a thing existing in the mind but not in reality (and therefore possible to assume that a conceptual structure itself can necessitate existence). The Form of something exists eternally, so it doesn’t matter if it ever actually exists in the world – it’s still rational. Existence is a predicate of the Form.
Aristotle: Particular things are primary to their forms (or “form inheres in matter”), and it is therefore impossible to think of a thing existing in the mind but not in reality (and therefore impossible to assume that a conceptual structure itself can necessitate existence). The form of something inheres in “the stuff”, so the thing must actually exist for its form to be intelligible. Existence is the pre-condition of the form.
I think this layout helps us understand the root of the issue. If you side with the Platonic tradition and affirm that the Forms exist eternally without regard for actual existence (essentially affirming some type of metaphysical immutability), then existence can be conceived as a predicate and the ontological argument makes perfect sense; however, if you align yourself with the Aristotelian tradition in affirming that the form of something inheres in matter, then you agree with a variation of the Kantian critique of Anselm: existence is not a predicate alongside others, it is their pre-condition.
It is also interesting to note that Aquinas the Aristotelian rejects the ontological argument as logically fallacious.
(Note: I understand that this is a rough generalization of Plato and Aristotle, and that its not entirely helpful to lump the Neo-Platonists in with the former or Kant with the latter, but as a broad schematic of options available, I think it works in illuminating the inherent difficulty in the ontological argument.)