Brains, Persons, and Society *** ABSTRACTS    Cervelli, Persone e Società ***ABSTRACTS

Universals, Tropes and philosophy of mind

             There is an ongoing debate in ontology between those who claim that the properties of concrete particulars are universals, typically exemplified by different particulars, and those who claim that they are tropes, particularized properties that can be exemplified by just one particular. According to the former, a predicate "F" stands for a universal F and thus, when we assert two true sentences such as "a is F" and "b is F" what make them true are, respectively, two distinct states of affairs or events which share one constituent, namely the property F. According to the latter a predicate stands for a class of tropes bearing to each other an objective relation of resemblance, which may be either perfect or partial. Thus, when we assert the true sentences "a is F" and "b is F" what makes them true are, two tropes, f1 and f2, respectively. Trope f1 is the only trope in the class of tropes corresponding to "F" which is instantiated by a. Trope f2 is the only trope in the same class which is instantiated by b. On purely ontological grounds, as the huge literature on the topic suggests, it is difficult to decide among these approaches, but typically the supporter of universals claims an advantage in terms of economy: she postulates a single universal where her opponent is committed to a large number of tropes and must perhaps even appeal to universals anyway, i.e.., resemblance relations among tropes.

            I wish to argue however that in the light of some problems in the philosophy of mind one could perhaps become more inclined  to prefer the trope alternative after all. In this area we want to distinguish between the type identity and the token identity theory. According to the former, a mental property such as being in pain and a physical property such as having C-fibers firing are identical. According to the latter, the mental event of x's having a mental property M is identical to an event such as x's having a physical property P. But if properties are universals this view is incompatible with the denial of the type identity theory, for how can the two events be the same if M and P are different? Yet, many think that the former is wrong and the latter right, in view of the multiple realizability problem: it seems that in principle a Martian not made up of organic matter and therefore endowed with, say, M-fibers rather than with C-fibers, could still suffer pain just like us. Now, if properties are tropes, one can say that the mental event of x's having a mental property M simply is a trope m in the class designated by "M" and this very trope can also be identified with the state of x's having a physical property P, for "P" might as well designate the same class of tropes as "M". This is compatible with the denial of the type identity theory and the possibility of multiple realization in the following sense. We can say that "having C-fibers firing" and "having M-fibers firing" correspond to two different classes of perfectly resembling tropes (to account for the diversity between the non-organic Martians and the organic creatures that we are). But the union of these two classes can still be taken to be a class of partially resembling tropes which we take to correspond to "being in pain" (to account for the fact that both we and the Martians, objectively and non-conventionally, experience pain). This is arguably more plausible than postulating a disjunctive physical universal such as having C-fibers firing or having M-fibers firing in order to claim that being in pain is identical to a physical property after all.

            Moreover, the fact that we are acquainted with our mental states, but not with those of other people seems to provide another  argument for resorting to tropes in philosophy of mind. For what does it mean to say that I am acquainted with my pain but not with yours? The supporter of universals seems to be committed to the following answer: I Am acquainted with an event involving myself and being in pain as constituents but not with an event involving you and being in pain as constituents. But this suggests that I am acquainted not just with being in pain but with myself, which is implausible, unless, perhaps, I am not a physical body, but a Cartesian soul (linked to a body). On the contrary, the supporter of tropes can simply answer that I am acquainted simply with a certain trope p1 (which can be exemplified only by me) but not with another trope p2 (objectively resembling p1 but exemplifiable only by you).