94 Peter McLaughlin
function ascriptions—intentional functions, etiological functions, and causal-role func-
tions—and see how they deal with normativity.
In intentional functions (where the function of an item is what some agent intends that
it do) it is possible that intentions could justify norms—perhaps only subjective norms,
though these might be intersubjectively binding. If something has been manufactured to
do something, then one can reasonably assert that it is supposed to do that something: a
screwdriver is supposed to turn screws. However, intentional functions are only found in
artifacts, or in nature, conceived as a divine artifact. Even in these cases we could just
replace “X is supposed to do Y” with “X was intended to do Y.” If anything more than
intent is meant by supposed, then it must still be justifi ed. The fact that someone wills or
intends some state of affairs does not of itself establish that state as a norm that ought to
be attained. One could even assert that the intentionality of intentional functions alone
cannot justify norms at all; even God’s intentions are normatively relevant only if he
intends things that a reasonable God should intend. For instance, when Descartes grounds
the conservation of force in God’s will, he insists that it is “consonant with reason” to
attribute this conserving action to God. A reasonable God would conserve the force and
matter in the universe (see McLaughlin 1993). But a reasonable God is one who conforms
to our postulated norms of rational (divine) behavior. It may be that certain normatively
distinguished intentions may ground the normativity of functions, but the norm-generating
capacity of these intentions must fi rst be explained.
In the case of etiological functions (where the function of an item is what its predeces-
sors have had the disposition to do), proponents tend to appeal to history, specifi cally to
a history of selection to explain the source of normativity. The etiological view of func-
tions is generally credited with the ability to explain plausibly why we can speak of mal-
function, and why we can say that some particular individual X, that in fact cannot perform
Y, nonetheless has Y as its function. For instance, if wings were selected for fl ight, we
may assert that a particular broken wing is supposed to enable fl ight but that it malfunc-
tions. Even opponents of the etiological view tend to give it some credit here. If an entity
was manufactured to do Y or was evolved to do Y, then that is its function. But if inten-
tions cannot ground norms, why should selection be able to ground them?
Proponents of the etiological view often hope that natural selection will provide the
normativity needed for their view of functions. The key element of Larry Wright’s original
analysis was the postulate that natural selection for a function can provide the normative
component of function ascriptions without presupposing intentional agents: “If an organ
has been naturally differentially selected-for by virtue of something it does, we can say
that the reason the organ is there is that it does that something” (Wright 1973: 159). As
Neander (1991b: 173) puts it: “The function of a trait is to do whatever it was selected
for.” Kitcher (1993: 383) agrees: “The function of X is what X is designed to do, and what
X is designed to do is that for which X was selected.” The idea is that something is sup-
posed to do what it was selected for doing. Although all hearts that pump blood also make