On Unifi cation: Taking Technical Functions as Objective 79
C. the agent a can justify these two beliefs on the basis of A; and
E. the agents d who developed p have intentionally selected x for the capacity to φ
and have intentionally communicated p to other agents u.A use plan p of an artifact x is a series of considered actions that includes at least one
action that can be taken as a manipulation of x, and that captures the use for which that
artifact is designed: using x can be described as the carrying out of a use plan p for x aimed
at achieving the goal associated with the plan.
With this defi nition, the ICE theory has by and large the form of the generalized
epistemic function theory Tep as given in section 5.4. The context c relative to which
technical functions are ascribed is a use plan. The evidence E agents are using to justify
their beliefs is formed by an account A, which typically consists of an amalgam of
technological and scientifi c knowledge about artifacts, hands-on experience with artifacts,
and information—testimony—about their use plans. The choice of the requirements
R 1 (xφc) and R 2 (xφc) is less straightforward. The I and C conditions together form an
epistemic condition of the form “agent a is justifi ed to believe on the basis of the account
A that... ” These two conditions can therefore be captured by an “R 2 (xφc) requirement.”
The E condition is not such an epistemic condition about beliefs of the agent a ascrib-
ing functions and seems therefore best to be captured by an R 1 (xφc) requirement. Yet
in current work on the ICE theory, the E condition is also phrased in the form “agent
a is justifi ed to believe on the basis of account A that... ” (Houkes and Vermaas 2009).
Hence one can take the original ICE theory as being of the form Tep with
c: the use plan p for x;
E: the account A about the use and designing of x and its use plan p;
R 1 (xφc): —
R 2 (xφc): • x has the capacity to φ when manipulated in the execution of p;- if this execution of p leads successfully to its goals, this success is due in
part to x’s capacity to φ; and - the designers d who have developed p have selected x for the capacity to
φ in p, and have communicated p to other agents u.
These choices defi ne the following ontological counterpart of the ICE theory:
An ontological ICE-function theory
Artifact x has the capacity to φ as a function relative to a use plan p for x, iff:
- x has the capacity to φ when manipulated in the execution of p;
- if this execution of p leads successfully to its goals, this success is due in part to
x’s capacity to φ; and - the designers d who have developed p have selected x for the capacity to φ in p,
and have communicated p to other agents u.