Psychological measurement is highly questionable but the details remain controversial: A response to Tafreshi, Michell, and Trendler

The profound and stimulating comments by Michell (2022), Tafreshi (2022), and Trendler (2022) push the measurement debate forward. Tafreshi provides arguments that are in line with my own position. While Michell is right in claiming that conceptualizations of psychological measurement are not necessarily Cartesian, I argue that the continuing influence of Cartesian thinking on conceptualizations of psychological measurement is evident in current definitions of psychological constructs. Moreover, I show that, contrary to Michell, it is meaningless to ask whether intelligence is quantitative. Michell and Trendler could counter this claim, but only at the cost of contradicting their stance that conceptual questions are not primary to the empirical questions surrounding psychological measurement. Beyond that, I contend that Trendler’s epistemological distinction of extensive versus intensive quantities does not compensate for the conceptual confusions inherent in his and Michell’s examples. Finally, I emphasize that all disputants agree that psychological measurement is a highly questionable idea.