On Unifi cation: Taking Technical Functions as Objective 73
subjective distinction, in ontological theories one focuses on functions as entities, which
may be ontologically objective or subjective entities; in epistemic theories one focuses on
ascriptions of functions as judgments, which may in turn be epistemically objective or
subjective judgments.
Cast in these terms, it is not problematic to adopt an epistemic theory of technical func-
tions since this does not rule out that an ontological theory also exists, but adopting a
theory that can merely be epistemic is better avoided if one aims at a uniform function
theory. That raises the question of how to avoid such exclusively epistemic theories. I do
not attempt here to analyze this latter question conclusively. I rather aim at showing that
for a specifi c class of epistemic theories of technical functions, one can construct coun-
terpart ontological function theories in which, moreover, judgments about technical func-
tions are epistemically objective. I fi rst make this plausible with a simple example; in the
next section I consider this construction of ontological function theories in general.
Consider fi rst the following technical function theory.
An epistemic design function theory
Agent a justifi ably ascribes the purpose φ as a function to artifact x relative to its
design iff agent a is justifi ed to believe that x was designed for purpose φ.
In this theory agents ascribe functions to artifacts on the basis of the intentions—“artifact
x is to be used for purpose φ”—of the artifacts’ designers, but it is left open whether or
not these functions are relations the artifacts have. The intentions relative to which func-
tions are ascribed do not depend on the ascribing agent a in any epistemic or ontological
sense, allowing the construction of a second function theory in which no reference is made
to this agent (references to the designers remain to be present, of course) and that is an
ontological function theory counterpart—in a sense to be determined—to the fi rst epis-
temic theory.
A counterpart ontological design function theory
Artifact x has the purpose φ as a function relative to its design iff x was designed for
purpose φ.
The fi rst epistemic design function theory does not imply this second ontological theory—
one can without contradiction add to the fi rst theory the further claim that technical func-
tions are not relations that artifacts have. Yet the ontological theory can be taken as
providing support to the fi rst epistemic design function theory by implying a third epis-
temic function theory that is a special case of the fi rst; and in this sense the second onto-
logical design function theory can be taken as a counterpart to the fi rst epistemic design
function theory. This third epistemic theory is derived from the second ontological design
function theory, and an appropriate theory about justifi cation, in the following way: if an
agent a is justifi ed to believe that an artifact x was designed for purpose φ, then the agent