I am scheduled to record a conversation with Pete Mandik for Philosophy TV tomorrow on higher-order approaches to consciousness and in the course of preparing for it I was rereading Pete’s Unicorn paper where, among other things, Pete gives several arguments that we are in fact able to think about non-existent objects. I do not think that we can.
It may seem quite natural to think that the answer to the above question is ‘yes’. For instance, we think of Count Dracula, unicorns, Santa Claus, and many other examples of this kind. If we take ‘thinking about’ to involve having some kind of relationship with the thing that is thought about this can seem crazy. If I am thinking about Santa Claus, for instance, that would mean that there would have to be some object that I was related to and since Santa doesn’t exist the object would seem to be a very strange one indeed! What should we conclude from this? Should we conclude that ‘thinking about’ doesn’t really involve a relationship between the thinker and the thing thought about?
Suppose that one accepted some kind of causal-historical account of the reference of (at least some of) our concepts and that thinking about x means tokening a thought containing a mental representation of x with the approriate causal-historical connection to x. So, to rehearse a familiar picture, Some child is born, his parents say “let’s call him ’Saul Kripke’”, other people are told “this is Saul Kripke” and thereby acquire the ability to refer to this child. Over time this name propagates, like a chain, link by link to us. So that when I think about Saul Kripke I employ a thought token that traces a causal-historical route back to the initial “baptism”. If this were the case, and one thought that natural kind terms worked like this as well, one would end up denying that we think about non-existent objects. The concept UNICORN has as its reference whatever it is that actually turns out to have been “baptized”. This may turn out to be a deformed goat, a hallucination, or maybe an imaginative act on the part of a person, whatever it actually turns out to be is what we are thinking about when we think about unicorns and that thing exists. So too for Dracula, Santa Claus, Jackalopes, etc.
But what about when we think thoughts like ‘there are no square circles’? Aren’t we thinking about square circles? I don’t think we are. Rather I think we are having an existentially quantified thought to the effect that nothing is both square and circular at the same time. Aha! Aren’t existentially quantified statements that are actually false examples of thinking about non-existent objects? If I think that the present King of France is bald, and there is no present King of France, are not I thinking about a non-existent object? Of course not! What you are thinking is that there is someone or other who is the present King of France and that is just plain, ordinary, boring false. There is no non-existent object which is correctly described as the one you are thinking about.
But isn’t denying that we can think about non-existent objects self refuting? What have we been talking about this whole time if not whether or not there are any of this kind of thought! So denying that there are any just shows that we have been thinking about non-existent objects all along! The very thoughts about non-existent objects that we have been discussing. But this is too quick. This is again just another example of an existentially quantified statement. ‘There are no thoughts about non-existent objects’ is really just saying that thoughts about non-existent objects don’t exist but that does not thereby mean that I am thinking about some non-existent objects! And this is for just the same reason as above; there are no objects which can be correctly described as the ones that I am thinking about.
So I am inclined to deny that we can think about non-existent objects…I am not saying that everyone should but only that there is a reasonable view, one that we ought to accept for other reasons not gone into here, and which denies that we think about non-existent objects. What this has to do with consciousness and Pete’s unicorn argument I will save for tomorrow’s discussion.