The episode of In Our Time that we listened to this week was perhaps a little brain-twisting for first thing on Sunday morning, but also in some ways appropriate for a Sunday! In it Melvyn Bragg and his guests (John Haldane (University of St Andrews), Peter Millican (University of Oxford) and Clare Carlisle (Kings College London)) discussed the Ontological Argument. This was put forward by St Anselm (Archbishop of Canterbury) in the 11th Century to prove the existence of God by logic alone. In this it is different from argument by design (ie the world works so well that it can surely only exist because someone designed it), or the cosmological argument (where the existence of the universe at all requires the existence of something that caused the universe to exist and this First Cause is God). In essence the Ontological Argument is that if God is by definition the greatest and most perfect concept that there can be, then he must exist because if he did not then there would be the possibility of a greater concept namely one that was all that God is but that also existed. So as God is the greatest, then he must exist. I think that’s the way it runs, anyway – as I say, somewhat brain-twisting.
It was criticised initially by some of his contemporaries, but continued to fuel others’ thought – later it was taken up by philosophers such as Descartes, Spinoza & Leibniz and criticised again by thinkers such as Hume & Kant. I was particularly struck by Kant’s criticism, which is that existence is not a predicate – he was answering in particular the formation of the argument that is saying that if God is the most perfect incarnation of all things (ie is perfectly knowing, is perfectly powerful etc), then he must necessarily also be perfectly existing as that is a quality that such a being must have. Kant was saying that existence isn’t a quality like the others – so you can describe an object, perhaps it is tall, blue and hairy. And then you can ask the question “and does it exist?”, this is a separate question to idea of what the object or concept is.
I can see the seductiveness of the Ontological Argument – both to bolster one’s own faith and to say to others “but you must believe, see I have proven it’s true!”. But to be honest it felt circular to me – it involved first defining God in such a way that his existence was part of the definition, and then saying “and therefore he exists”. I’m sure there are more subtleties to the idea than that, however, otherwise it wouldn’t’ve occupied so many people’s thoughts for so long.