The tempting thought is that a necessary condition for an English sentence to be
metaphysically possible is either for it to have a translation into the metaphysically
perfect language or for the metaphysically perfect language toshowthat it is true.
Once we understand the rules and limitations of the metaphysically perfect language,
we can see that it shows that no electrons have members and that all sets are non-
charged. I’m hesitant to rest things on this distinction, but it would be interesting if
this were the best move to make.
Before moving on, let us raise the interesting, albeit largely terminological, ques-
tion of whether we should reserve“ontological category”for those modes of being
that impose type-restrictions of the sort used here or rather use the phrase inter-
changeably with“mode of being.”(We could, if we liked, call the former“strict
ontological categories.”) Adopting this terminology might bring the view explored
here closer to the Aristotelian tradition that inspires it. I think Aristotle’s notions of
potentialityandactualitycorrespond to modes of being, but he does not call them
“categories”; those are reserved for the modes of being of substances and the various
kinds of accidents.^56
Finally, as noted in section 1.5.3, for many applications of ontological pluralism, it
doesn’t matter much whether modes of being are understood in terms offirst-order
properties or in terms of kinds of quantification. But if we want to defend a view like
the one defended in this section, it seems that we are better served by taking modes of
being to correspond to kinds of quantification.
4.6 Formal Ontology
Let’s now discuss the ramifications of the neo-Aristotelian view of ontological
categories for the putative discipline offormal ontology. The key question is whether
formal ontology ineliminably presupposes thatobject/entity/thing, understood as the
most general covering kind for anything that there is, is an ontological category. On
the neo-Aristotelian view, it is not, and hence the possibility for tension.
What then is formal ontology? There are many reasonable things one could
mean by this expression. Formal ontology as I will understand it isnotmerely the
discipline of philosophy that applies formal methods to ontological questions. I have
no qualms about the applications of formal methods to ontological questions, and
the neo-Aristotelian view does not in itself imply that such an application would
be methodologically improper.^57 Rather, I construe formal ontology as the putative
discipline that describes the perfectly natural topic-neutral features that are
(^56) Similarly, Witt (2003: 3) distinguishes between what she calls“kinds”of being that correspond to
categories and 57 “ways”of being that include potentiality and actuality.
Nor do I have qualms about the discipline called“formal ontology”by Cocchiarella (1969, 1972),
which studies the foundational principles governing the various modes of being. I welcome such a
discipline!