Friedman's answer to this question is:
"[T]here inevitably will remain room for judgment in applying the rules. Each occurrence has some features peculiarly its own, not covered by the explicit rules. The capacity to judge that these are or are not to be disregarded, that they should or should not affect what observable phenomena are to be identified with what entities in the model, is something that cannot be taught; it can be learned but only by experience and exposure in the "right" scientific atmosphere, not by rote. It is at this point that the "amateur" is separated from the "professional" in all sciences and that the thin line is drawn which distinguishes the "crackpot" from the scientist." ["The Methodology of Positive Economics," p. 25]
recognition" that precedes "good sense", "the process of prediction" [Difference and Repetition, p. 285] deployed on a scientific level. It is based upon an education in "the 'right' scientific atmosphere;" in particular, it is based on the specialization of "professional" schooling where an instrumental confinement to the diagram is embedded as a way of life. [see, "Re-Imagining the Academy: Louis Menand"] The problem is that it blinds its adherents to alternative diagrams, to there even being alternative diagrams, to different interpretations of the same situation, and it allows the importation of diagrams, with often tragic results, into situations where they do not apply. Any diagram is a selective abstraction, one among several, and there is always the question whether it applies or not.