ABSTRACT

Aquinas has a special problem in giving an account of intellectual knowledge of individuals because of his thesis that individuation is by matter. Some philosophers have thought that an object could be individuated by listing the totality of its properties. Since to have a property is to fall under some universal – to be square, for example, is to be an instance of the universal ‘square’ – if an item can be individuated by its properties, all we need to identify an individual is to list the universals under which it falls. But Aquinas rightly rejected this: in theory, however long a list of universals we draw up, it is always logically possible that more than one individual will answer to the list.