Peter Auriol (d. 1322) and the Later Medieval Debate on Mental Being, 1315-1350.

When I think of a rose, there is a sense in which that rose exists in my mind as the object of my thinking about that rose. The same is true of my thinking about a unicorn except for the fact that there is no being in external reality that is a unicorn. Even if roses uncontroversially exist “out there” and unicorns do not, what about the mental rose and the mental unicorn, which somehow exist in my mind? What kind of being do they have? In the later Middle Ages, the kinds of being that were usually recognised were the ten Aristotelian categories (substance, quality, quantity, etc). Did mental being fit into the Aristotelian categories? A decisive figure in promulgating the view that mental beings enjoy a peculiar sort of existence, not easily slotted into one of the categories was the Peter Auriol (c. 1280-1322), who claimed that mental beings of all types have "objective existence", i.e. existence as an object of the intellect, fundamentally different from extra-mental existence. Auriol's metaphysics of the mental realm was instantly divisive, garnering significant criticism the depths of which have yet to be assessed. This project aims to trace the reception of Auriol’s innovative but metaphysically disturbing account of mental beings and mental existence at Oxford and Paris respectively. This debate on the mental being(s) attests to the creativity of medieval philosopher-theologians in thinking beyond the metaphysical framework that they inherited from Aristotle.