Cumulative Record. Chapter 34: The Generic Nature of the Concepts of Stimulus and Response. Quote 3

. . . the existence of a popular term does create some presumption in favor of the existence of a corresponding experimentally real concept. But this does not free us from the necessity of defining the class and of demonstrating the reality if the term is to be used for scientific purposes. It has still to be shown that most of the terms borrowed from the popular vocabulary are validly descriptive—that they lead to a consistent and reproducible experimentation. (p. 520)