78 Pieter E. Vermaas
one is still not committed to accepting Tont; there may be ontological theories different
from Tont that are also consistent with T ′ep.
Fifth, Tont for specifi c choices of c, E, R 1 (xφc), and R 2 (xφc) provides support to Tep for
those choices: acceptance of Tont is implying acceptance of T ′ep, which is a special case of
Tep.
Sixth, if the judgment whether the requirements R 1 (xφc) and R 2 (xφc) hold does not
depend on the attitudes, feelings, and points of view of the agents making the judgment,
then functions in both T ′ep and Tont are epistemically objective. For Tont, this conclusion
follows directly. For T ′ep, the conclusion follows by noting that in this case the truth of
the judgments of whether R 1 (xφc) holds and of whether it is justifi ed to believe that R 2 (xφc)
by E also does not depend on one’s attitudes, feelings, and points of view.
In summary and emphasizing the results that I use in the second half of this contribu-
tion: if an epistemic function theory fi ts the generalized form Tep, one can then construct
a counterpart ontological theory by the generalized form Tont; in this counterpart ontologi-
cal theory, functions are epistemically objective if the judgment whether the requirements
R 1 (xφc) and R 2 (xφc) hold does not depend on the attitudes, feelings, and points of view
of the agents making the judgment.
5.5 An Ontological ICE-Function Theory
Using the results of the previous section, I am in the position to construct an ontological
counterpart to the ICE-function theory. Wybo Houkes and I proposed the ICE theory as
an analysis of specifi cally technical functions after arguing that the main alternatives,
including intentional theories, Cummins’s theory, and etiological theories, failed to meet
simultaneously four desiderata for theories of technical functions (Vermaas and Houkes
2003). Yet the ICE theory is explicitly an epistemic function theory that provides condi-
tions under which agents are justifi ed to ascribe technical functions to artifacts, and in turn
evokes the criticism that it does not determine what technical functions are ontologically.
An ontological counterpart to the ICE theory would meet this criticism—that is, if it is
acceptable as a theory of technical functions—and, moreover, would limit the differences
between biological and technical functions to that between ontological objectivity and
ontological subjectivity.
The central defi nition in the original epistemic ICE theory reads
The ICE-function theory
An agent a justifi ably ascribes the capacity to φ as a function to an artifact x, relative
to a use plan p for x and relative to an account A, iff:
I. the agent a has the capacity belief that x has the capacity to φ, when manipulated in
the execution of p, and the agent a has the contribution belief that if this execution
of p leads successfully to its goals, this success is due, in part, to x’s capacity to φ;