I was thinking about the modal ontological argument’s controversial possibility premise; the premise which says that it is possible for God to exist. However, an ontological argument against the existence of God can work just as well if one merely accepts the opposite possibility premise; namely, that it is possible for a maximally great being to not exist. The difficulty here is that seems incredulous to say that a maximally great being, whose idea involves existence, does not exist, but one can legitimately argue their way to this conclusion. This can be done in three ways. First, one can argue that the concept of a maximally great being involves self-referential incoherence, such that two or more of God’s attributes are flatly contradictory. Second, one can argue that the concept of a maximally great being is logically incompatible with some rationally necessary and foundational belief; a belief, in other words, which it would be irrational to ever abandon. Finally, one can plead a cognitive handicap by saying, as many ‘positivists’ do, that the term God does not correspond to any coherent or graspable concept.
I think all attempts to impugn the credulity of the possibility premise by either of the first two ways have been recognized by the majority of the thinking community to be miserable failures. However, what of the third avenue?
Here, I came to think recently that it is always more epistemologically prudential to accept as a possibility anything which cannot be demonstrably shown impossible. This idea is similar to the idea I’ve proposed in an earlier post about it being more epistemically prudential to assume compatibility of beliefs until contradiction has been clearly demonstrated. Similarly I suspect that the assumption that something is possible unless or until the impossibility of it is demonstrated is more epistemically prudential. This may give us an epistemological argument for accepting the possibility premise of the ontological argument. The danger here is parody – that one could simply say that it is ‘possible’ that a maximally great being not exist, and that possibility premise would work in an ontological argument proving the non-existence of God. However, I think that fails in this case, and I want to offer two reasons why. First, I think the rule I’ve just laid out here has implicitly to do with positive possibility, since it wouldn’t do anybody any good to have an epistemological rule of thumb which restricted logically possible worlds (notice that the set of logically possible worlds may be greater than the set of worlds which I am now capable of imagining).
For the positivist to say that she has no idea what the term ‘God’ means is not, if my argument above is correct, a legitimate way to dodge the conclusion that God exists. Consider that we should all accept the possibility that there is some colour which we have never seen, and which we have no means of imagining – even if we have no idea in our minds corresponding to such a colour, we ought to, as a matter of epistemological prudence, believe that such a colour possibly exists. A colour-blind person, for instance, might have to admit that there are colours which they have never seen, though other people report experiences of seeing them, even while they haven’t the foggiest idea what such colours would look like. Similarly when the positivist claims a cognitive handicap because she has no idea what the term ‘God’ means, she has not provided an excuse for not assuming that the existence of God is possible, and thus she has no way of escaping the conclusion rationally that God exists. She must maintain that ‘God exists’, and that she is theologically colour-blind. Even in a world where nobody had a concept of a maximally great being, the belief in the possibility of a maximally great being would be epistemically prudential.
So the first reason the parody doesn’t work is that the rule is intended for positive possibilities (or that which furnishes more entities in the realm of logically possible worlds, rather than fewer entities).
The second reason the parody won’t work is that it is not conceptually possible for a maximally great being to exist – for anyone who understands the concept recognizes that existence is entailed by maximal greatness. Thus to think that – for any proposition P and any subject S, if S can conceive of P then S can conceive of ~P – is clearly not true in this case, just as it is not true in any cases involving necessary propositions.
My train of thought in this direction was pushed somewhat by reading a very interesting post on the ontological argument which attempted to provide an apologetic (to which I will here provide a link) for the possibility premise in another way, and one which I’m still considering. I had a feeling at first that it may have been confusing or conflating epistemic possibility with modal possibility (for instance, it is not logically possible that ~(2+2=4), and yet it is epistemically possible that my belief that 2+2=4 is false). However, I am not sure. In any case, the argument I’ve provided is clearly a prudential and epistemological one, and not, strictly speaking, a modal one. Thus, to escape the conclusion one merely has to adopt an epistemic attitude which is, I think, imprudent.