On Unifi cation: Taking Technical Functions as Objective 77
form Tep by choosing c, E, R 1 (xφc), and R 2 (xφc) appropriately, then one can arrive at an
ontological function theory by substituting those choices into the generalized form Tont.
This ontological theory Tont provides support to the epistemic function theory Tep: Tont
implies a third epistemic function theory T′ep associated to Tont that is a special case of Tep
and that has the following form:
An epistemic function theory T′ep associated with the ontological function theory
Tont
Agent a justifi ably ascribes the capacity to φ as a function that x has relative to
context c and relative to evidence E for R 2 (xφc) iff R 1 (xφc) and agent a is justifi ed to
believe on the basis of E that R 2 (xφc).
In the next section I use this suffi cient condition to construct an ontological counterpart
to the ICE-function theory. But before doing this, I add brief remarks on the relations
among Tep, Tont, and T ′ep.
First, if one accepts Tep for specifi c choices of c, E, R 1 (xφc), and R 2 (xφc), then one is
not necessarily committed to accepting the ontological theory Tont for those choices: one
can accept Tep but simply deny Tont by holding that functions are not real relations that
artifacts have.
Second, if one accepts Tont for specifi c choices of c, E, R 1 (xφc), and R 2 (xφc), then
one also can accept the associated epistemic theory T′ep. Proof of the “if” part of T′ep: If
R 1 (xφc) is the case and an agent a is justifi ed to believe by E that R 2 (xφc), then by Tont one
can conclude that a is justifi ed to ascribe the capacity to φ as a function that x has relative
to c and relative to E. Proof of the “only if ” part of T ′ep by ad absurdum: Assume that a
may ascribe the capacity to φ as a function x has relative to c and relative to evidence E
for R 2 (xφc). Suppose then that it is not the case that “R 1 (xφc) and a is justifi ed to believe
on the basis of E that R 2 (xφc).” This supposition implies that R 1 (xφc) is not the case or
that a is not justifi ed to believe on the basis of E that R 2 (xφc). If R 1 (xφc) is not the case,
then by Tont agent a cannot ascribe the capacity to φ as a function to x relative to c and
relative to any evidence for R 2 (xφc). If a is not justifi ed to believe by E that R 2 (xφc), then
by Tont agent a cannot justifi ably ascribe the capacity to φ as a function to x relative to c
and relative to that evidence E. Hence the supposition cannot be true, meaning that it is
the case that R 1 (xφc) and agent a is justifi ed to believe on the basis of E that R 2 (xφc).
Third, if one accepts T ′ep for specifi c choices of c, E, R 1 (xφc), and R 2 (xφc), then one is
not necessarily committed to accepting Tep for those choices: T′ep is only a special case of
Tep in which functions are real relations artifacts have.
Fourth, if one accepts T ′ep for specifi c choices of c, E, R 1 (xφc), and R 2 (xφc), then one
is not necessarily committed to accepting Tont for those choices: T ′ep allows agents a to
ascribe functions to artifacts that those artifacts do not have in Tont, for instance, when
agents are justifi ed to believe R 2 (xφc) on the basis of evidence E for R 2 (xφc) that is actu-
ally incorrect, such that R 2 (xφc) is actually not the case. And even if R 2 (xφc) is the case,