Armstrong on Determinable and Substantival Universals

Abstract

One of the most attractive aspects of David Armstrong’s book Universals and Scientific Realism is the way it ties the topic of universals to the understanding of causation, explanation and natural laws. Its most exciting thesis, in my opinion, is that natural laws are not universal generalizations (as understood in contemporary logic and as the neo-Humeans claim) but rather express a non-extensional relation between universals, a relation he calls “nomic necessitation”. However, it is precisely the part of the book that defends this thesis which convinces me that Armstrong in all consistency ought to have been a much less restrained realist than he in fact is.