  Now perhaps it will be suggested that, in the absence of any property or accident of Socrates to correspond to the concept ‘thought about’, Socrates himself can serve as the correspondent. In that case, however, we should have to admit that an individual substance is a relation (since, as we have seen, whatever corresponds to a relational concept and plays the relevant metaphysical role qualifies as a relation). But such an admission goes against deep-seated intuitions deriving from the Categories.  As we have seen, Aristotle not only assumes that relations are accidents in the Categories, but intentionally characterizes them in such a way as to exclude substances from this category. But then we still lack a solution to our problem. If there is no property or accident of Socrates to correspond to the concept ‘thought about’, and neither Socrates nor a property of anything else can correspond to it, what if anything can?