 Already in his paper on “Operational Analysis” Bridgman (1938, 115–116) had stated that in the attempt to understand how science works, “the subject matter … is activity of one sort or another”. He equated “activity” and “operations”, the term “operation” only accentuating the directedness of the activity in question. In his last general philosophical treatise, The Way Things Are, Bridgman came back to this theme and stated that an operational analysis was only “a particular case of an analysis in terms of activities—doings or happenings”, instead of analysis “in terms of objects or static abstractions”, or “in terms of things or static elements” (1959a, 3; also 1959b, 522).