 He defends against this by requiring only certain phenomena of interest to be explained, but as Samuelson pointed out, this can lead to unscientific cherry-picking of results.Samuelson dubbed Friedman's principle the F-Twist, avoiding naming it after Friedman directly out of courtesy.Daniel M. Hausman described "The Methodology of Positive Economics" as "the most influential work on economic methodology of [the twentieth] century."