Reading Valicella’s discussion of Twardowski’s ‘solution’ to the paradox of intentionality brought to mind my old translation of Ockham’s commentary on Aristotle’s Perihermenias. The whole thing is worth a read, but section 9 is particularly relevant.
Replying for those who say that an intentional object is a real being, Ockham argues that 'a chimaera exists in reality' has distinct meanings according to whether 'chimaera' denotes personally, or materially or simply. If it denotes personally (i.e. if it is meant to denote a chimaera itself) it is false. But if it denotes ‘materially’ (i.e. if it stands for the word 'chimaera') or ‘simply’ (it stands for the concept of a chimera), it is true, for the word 'chimaera', and the concept chimaera both exist in reality. Similarly the proposition 'a chimaera is understood' is false, if 'chimaera' is meant to stand for a chimaera, but true, if it stands either for the word itself, or for the concept of a chimaera. (An argument he repeats in Summa Logicae II.72). This solution seems close to the one that Twardowski criticises. When I think about the round square or the golden mountain (in whatever psychological mode) the object of my thought is neither a mental content nor an abstract object. And ‘the golden mountain’ refers to the golden mountain, not, as Ockham’s comment suggests, to the concept of a golden mountain.
Note Ockham’s use of the example ‘golden mountain’ (mons aureus). I can find only one earlier example, in Scotus’ questions on the Metaphysics (q.6), written in the late 1290s, but it must surely be older than that.