can do the jobs that naturalness has been invoked to do, and hence in that respect,
they do not differ in their theoretical roles.
Second, let me concede that one legitimate role that properties can play is to serve
as meanings. And if we take triangularity and trilaterality to be properties playing this
role, they are numerically distinct since their corresponding expressions differ in
meaning. But then so too are the properties of being water and being constituted by
H 2 O molecules. And even if we want to distinguish between these properties, in some
sense the phenomena are the same. Moreover, the sense in which the phenomena are
the same is not merely that necessarily every token of one is a token of the other and
vice versa. Suppose that necessarily everything extended is colored and vice versa; the
phenomena of extension and color are nonetheless not identical. I am interested in
properties and relations better understood asreferentsof predicates rather than as
theirmeanings. It may well be that there are necessarily equivalent yet non-identical
properties even when conceived in this way; in fact, I think that there are. On this
conception of properties, however, being water and being constituted by H 2 O
molecules are not merely necessarily coextensive properties, but rather are identical
and have been discovered to be so. My view is that we can also discover identities of
properties so conceived via philosophical reflection.
However, if I am wrong about this, there is still an interesting question about
priority to be settled, and the next two sections attempt to answer this question.
7.5 Is Naturalness the Prior Notion?
I’ve sketched a case for the NVH. But we shouldn’t immediately embrace the NVH,
for there might emerge reasons to think that one notion is in some way prior to the
other. We can define“grue”and“bleen”in terms of“blue”and“green”(plus some
other machinery), but“blue”and“green”can also be defined in terms of“grue”and
“bleen”(plus the same machinery). But it doesn’t follow from this fact that a theory
stated using“green”and“blue”is just a notational variant of a theory stated in terms
of“grue”and“bleen.”“Green”and“blue”aremetaphysicallyprior to“grue”and
“bleen,”soought to beprior in definition as well. A theory that takes the notion of
“grue”asundefinedis making ametaphysicalmistake.
Let’s examine two arguments for taking the notion of naturalness rather than
degrees of being as themetaphysicallyprior notion.
Thefirst argument is themeta-Euthyphro argument. Two properties are not
metaphysically on a par simply because they mutually supervene on each other.
Euthyphro puzzles arise whenever we suspect that one of the properties is more
fundamental than the other. Is the fact that it is morally obligatory why God
commands that it be done, or does God’s commanding that it be done make it the
case that it is morally obligatory? The question“which property,being morally
obligatoryorbeing commanded by Godisprior?”is intelligible, and tough to answer