There is an important intersection between the 14th century debate about realism and nominalism and contemporary questions about the status of modality in logic that ought to be of interest to non-specialists. Both of these topics probably sound obscure to most people. At sound-byte level, the first is about the status of universals, and modality is something we implicitly presuppose any time we try to reach for something “more” than allegedly pure phenomena or mere appearance.
Both sides of the medieval debate often wanted to enlist the support of Aristotle, who took a remarkably even-handed approach to these questions we have yet to clarify. The debate was often invested with a great moral significance, and provoked a number of intemperate claims. But at the same time, both sides were able to use the technical vocabulary of the theory of “supposition” — along with shared familiarity with Aristotle — to discuss semantic issues of concrete meaning and word use in detail, in terms both sides could in large measure agree upon. This led to a very high quality and sophistication in many contributions to the debate on both sides.
On some slight acquaintance, many modern readers can easily sympathize with nominalist critiques of the premature and illegitimate use of universals. We may think of vulgar platonism, excessive abstraction, reification, alienation, and so on. On the other side though, there are premature and illegitimate claims that universals can be explained away entirely. But Hegel’s Frau Bauer could not even recognize her individually named cows, if there were no such thing as legitimately reusable reference, naming, and vocabulary. I think most people should be able to see that there are two sides to the coin here.
If we ask how legitimate repeatabilities in ordinary language are constituted and used, something like modality inevitably comes into play. It now occurs to me that Brandom’s emphasis on the priority of hypotheticals over alleged categoricals in real-world material inference — a point to which I am deeply sympathetic — really calls for something like the notion of modality that he develops.
The Postmodern Peripatetic 