Abstract

We have seen that the operational imperative is a prescriptive thesis about formulations of theories which imposes restrictions on the sorts of theories science may employ. We assessed the operational imperative by investigating a number of relationships holding between theory formulations, theories, physical systems, and phenomena, and then applying our findings to the operational imperative. These applications showed that the operational definitions required by the operational imperative were not definitions at all, being rather statements of putative empirical regularities holding between particulars which in effect are formulations of empirically true or false theories. From this fact it followed that the supposed epistemic pay-offs of following the operational imperative fail to accrue: Operational definitions do not enable one to go deductively from knowledge of observables to knowledge of unobservables, and operational definitions do not provide a means for testing theories about unobservable phenomena. As such the operational imperative should be rejected in both its weak and strong versions. However, we did discover a grain of truth in the observational imperative — namely that theories with non-observable parameters are testable only if these parameters have observable manifestations. But that grain of truth does not lead to the operational imperative as typically advanced unless one embraces certain epistemological theories about observation which recent work on observation makes highly doubtful