Reviel Netz, in his new book Why the Ancient Greeks Matter, Cambridge University Press, 2025, goes out of his way to frame half the book as a refutation of alleged “errors” in Kuhn and Koyré:
“Koyré and Kuhn are wrong” (70)
“Koyré and Kuhn were wrong” (76)
“once we clear up this error” (126)
“Kuhn’s first implicit error” (126)
“Because of his error … Kuhn ended up assuming” (126)
“hard to believe that Kuhn could have been so wrong” (126)
“Kuhn did not notice” (126)
“Kuhn was just incredibly wrong” (127)
“Kuhn missed this fact … This was truly his blind spot” (129)
“Kuhn could not understand” (129)
“Kuhn rather misses the point” (134)
“[Kuhn] was badly wrong” (134)
“Kuhn … got wrong” (177)
Netz provides essentially no evidence that Kuhn and Koyré actually held the views that he finds it convenient to attribute to them. You would think that, if you insist again and again and again and again and again and again and again and again and again and again and again and again and again on how “wrong” a particular scholar was, then it would be appropriate to provide references to support these accusations. But Netz is evidently exempt from having to do so.
Unlike Netz himself, let us compare his accusations with what Kuhn and Koyré actually said.
“Before Copernicus, there was, so they claimed, one Aristotelian-Ptolemaic worldview. … Koyré and Kuhn are wrong in their understanding of antiquity. It is perfectly reasonable to say that early modern Europe was heir to an Aristotelian-Ptolemaic paradigm. This paradigm, however, was not ancient. It was medieval, … transforming the many ancient philosophies … into a single teachable monolith. When modern scientists broke up the Aristotelian-Ptolemaic worldview, they returned to the ancient ways of contentious science.” — Netz, Why the Ancient Greeks Matter, 70
“Koyré and Kuhn were wrong to think of the Aristotelian paradigm as ancient. There was no ancient paradigm and revoking the Aristotelian medieval paradigm was indeed a move back into antiquity itself.” — Netz, Why the Ancient Greeks Matter, 76
Koyré and Kuhn were not wrong. They said exactly what Netz is saying:
“The task of the medieval scholar was … complicated by a foreshortened historical perspective. He expected to reestablish a broad and coherent system of knowledge modeled on Aristotle’s, and he did not always recognize that the ‘antiquity’ from whom the system was to derive had had a number of different opinions about a great many questions of detail.” — Kuhn, Copernican Revolution, 103
“Because their ignorance of the preceding centuries had telescoped their sense of history, the scholastics viewed Aristotle and Ptolemy very nearly as contemporaries. They appeared as exponents of a single tradition, ‘ancient learning’, and the differences between their systems became very like inconsistencies in a single body of doctrine.” — Kuhn, Copernican Revolution, 105
“In the ancient world there were other schools of scientific and cosmological thought, apparently little influenced by Aristotelian opinion.” — Kuhn, Copernican Revolution, 83
“Nor had [Aristotle’s] contemporaries accepted all his views. Occasional equivocations and contradictions had characterized the ancient tradition from the start. … To us these inconsistencies in the tradition seem natural products of its evolution and transmission, but to the medieval scholar they often appeared as internal contradictions in a single body of knowledge, the hypothetical unit ‘ancient wisdom’.” — Kuhn, Copernican Revolution, 104
“Medieval Aristotelianism is not that of Aristotle. … The reason [for Aristotle’s influence in the Middle Ages] is quite easy to understand. First, Aristotle was the only Greek philosopher whose entire work … was translated. … Aristotle’s work forms a veritable encyclopedia of human knowledge. … It is not surprising that, for the High Middle Ages, dazzled and overwhelmed by this mass of knowledge, …. Aristotle became the representative of truth. … Aristotle, moreover, is a godsend for the professor. Aristotle teaches and is taught; he is discussed and commented upon. It is therefore not surprising that, once introduced into schools, he immediately took root there.” — Koyré, Études d’histoire de la pensée scientifique, 32, 18-19
Another false claim by Netz:
“Positing an ancient paradigm, Kuhn did not notice that Aristotle’s cosmology was, in important ways, in flagrant contradiction to Ptolemy’s. Aristotle assumed a model of nested, perfect spheres … Ptolemy, on the other hand, … had a complex system of circles mounted upon circles. … [This is] no mere technical detail. It is really very hard to be a Ptolemaic and an Aristotelian at the same time.” — Netz, Why the Ancient Greeks Matter, 126-127
Kuhn did notice exactly this:
“One of the inconsistencies embedded in the tradition played a particularly significant role in the development of astronomy: the apparent conflict between the spheres of Aristotelian cosmology and the epicycles and deferents of Ptolemaic astronomy.” — Kuhn, Copernican Revolution, 104
“The set of epicycles and deferents, which replaced homocentric spheres for purposes of mathematical astronomy, did not fit very well into crystalline spheres like those proposed by Aristotle. … It is not, for example, clear from the Almagest whether Ptolemy believed in them [i.e., Aristotelian spheres] at all.” — Kuhn, Copernican Revolution, 80