In 1948 Hempel and Oppenheim proposed an explicatum for the concept of systematic power 1, pp. 164–167. Since that time some shortcomings have been found in this first attempt. It is the purpose of this paper to show that one can keep the basic approach of the ‘48 paper, and overcome the known disadvantages by means of changes in the details of the definition. In this improvement certain tools will be used that were not available in 1948.

We wish to give a precise formulation of the intuitive concept: The degree to which the known facts support a given hypothesis.

1. The problem. The concept of confirmation of an hypothesis by empirical evidence is of fundamental importance in the methodology of empirical science. For, first of all, a sentence cannot even be considered as expressing an empirical hypothesis at all unless it is theoretically capable of confirmation or disconfirmation, i.e. unless the kind of evidence can be characterized whose occurrence would confirm, or disconfirm, the sentence in question. And secondly, the acceptance or rejection of a sentence which does represent an (...) empirical hypothesis is determined, in scientific procedure, by the degree to which it is confirmed by relevant evidence. (shrink)