Ken writes: In Act 2, Scene 2 of Shakespeare’s eponymous play, Hamlet explains “[…] for there is nothing either good or bad, but thinking makes it so […]” This is a statement of mind-dependence. Certain qualities of things, in this case whether Denmark is like a prison, are not inherent in their objects but are projected on to them by perceivers. We sometimes say they lie in the eye of the beholder. It is typically aesthetic properties of things, their ugliness or beauty etc, that are thought to be mind-dependent in this way, although some philosophers have said moral properties of objects and actions, and certain sensed qualities of things (such as colour or temperature), are also mind-dependent.
Traditionally, there is another field where the notion of mind-dependence is deployed and that is the old scholastic debate over the existence of universals (or more generally of abstract (as opposed to concrete) objects). The traditional debate concerns whether we need to postulate a property or ‘universal’ to explain agreement in attribute among distinct particular objects. Particular things, though numerically distinct, are quite often the same in quality, or as we say, they agree in attribute. The two socks I put on this morning, fortunately, are both light blue. The books on my desk are all (the same in respect of being) books. Realists in the traditional debate thought that to account for the similarity we need to recognise universals as the things that the distinct particular objects have in common. So as well as there being seven books, on my desk say, there is also the universal form of the book (though the form itself is not on my desk -in fact it isn’t anywhere). Realists think universal forms are necessary to ground the truth that the several books are all the same (where there is a truth, there must be something objective and real that makes it true). Nominalists, on the other hand, deny that there is anything in addition to the particular books. There is nothing they really have in common as they are all distinct particulars (other than the fact that we call them all by the same name, which is why nominalists are called ‘nominalists’ -from the latin word for a name). But why do we call them by the same name? If we had called them by different names would they have been more different? Conceptualism, or the view that universals are mind-dependent, is usefully thought of as a way to answer these questions. It holds that the particular books are really distinct, but that we project the similarity on to them, or see a similarity in them that causes us to group them together as members of a common kind. So conceptualism is the view that not just ugliness and beauty but all qualities, attributes, dimensions, (in short all similarities between distinct objects) are in the eye of the beholder.
Maybe this isn’t really a coherent position, but it has been seriously maintained throughout the history of philosophy. The question I’m wondering about at the moment is what happens to this idea if we accept the mind-brain identity thesis. This states that the mind just is the brain, and that every particular thought or feeling is identical with some particular neurological state. Does this collapse conceptualism into realism or into nominalism? It might be thought to collapse into nominalism because how should the mind’s being a physical thing bring abstract universals on to the scene? But against that, if the mind was responsible for grouping particular objects into kinds, and it turns out that the mind is a real physical thing too, then some real physical thing groups objects into kinds and isn’t this a kind of realism (you have a truth (such and such things are grouped together) and a thing, a neurological structure, that makes it true)?
And the title of the post pertains to the generalisation of this question. If the mind is a physical thing, then do apparently mind-dependent relationships just vanish, or should they be seen as really there?