The Essentialist Aspect of Naive Theories - Michael Strevens

Finally, the fifth defense of pure essentialism is to suggest that water is
represented as having an essence other than “at least 70% (or some other
proportion) H 2 O”. This goes against the usual essentialist line (see especially
Atran (1990)) that as children mature into adults, their theories become
more and more like the currently accepted scientific theories, since if
chemistry attributes any essence to water, it is H 2 O. But suppose that, for
the sake of saving the hypothesis, the pure essentialist retracts this claim.
Then pure essentialism owes us some suggestion as to what the represented
essence of water is, such that it includes swamp water, the stuff in
a radiator, and sewer water, but not tea, blood, or grapefruit juice. There
is a very strong constraint: the K-patterned projections and especially the
K-patterned categorizations rule out appearances and behavior as possible
constituents of this essence. Thus a description of the essence must not mention
the appearance or the chemical behavior of water. But what do people
know of water, apart from its look, its behavior, and the fact that “water
is H 2 O”? Nothing. If there is something that is widely believed to be the
essence of water, and that has nothing to do with looking like water or behaving
like water, it must be something to do with H 2 O. But what could
that something be but the proportion of H 2 O? There may be something
that I have not thought of; it is up to the pure essentialist to say what it is. I
might add: since we all represent water as having this essence, why doesn’t
it spring to mind when summoned?
Before concluding, I will make one more point in favor of the minimal
hypothesis. The minimal hypothesis suggests a partial explanation of the fact
that some things with high H 2 O content are not counted as water. It will be
noted that the non-waters—such as tea, juice, blood, and disinfectant—have
special chemical (or biochemical) properties in addition to those possessed
by water. It is our knowledge of these additional properties, I tentatively
suggest, that prevents us from categorizing the fluids as water. For example,
we know the following causal law: disinfectant kills germs. But we also know
that this law is not true of water. So we infer from the germ-killing ability of
disinfectant that it is not a kind of water. 28,29
28. The full story must be considerably more complicated than this. For example, chlorinated
tap water is a kind of water, but chlorinated water also kills germs (if much less
effectively). Or consider: there are causal laws about sewer water (it smells bad) that are
not true of water in general.
29. Essentialists can offer the same explanation. But although we may infer, defeasibly,
from the special properties of coffee that it is not water, if we also believe (a) that coffee is
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