 The focus of the epistemological issues could be ranked mutatis mutandi with modern discussion surrounding the scientific status of astronomical theories (however, as Jardine has pointed out, it would be sounder to read Kepler’s CU more as a work against skepticism than in the context of the modern realism/instrumentalism polemic). For Pierre Duhem (1861–1916), for instance, the position of Andreas Osiander, which was adopted by Ursus and which was, according to Duhem, naively criticized by Kepler in his MC, represents the modern approach known as “instrumentalism”. According to this epistemological position, held by Duhem himself, scientific theories are not to be closely linked to the concepts of truth and falsehood. Hypotheses and scientific laws are nothing more than “instruments” for describing and predicting phenomena (seldom for explaining them). The aim of physical theories is not to offer a causal explanation or to study the causes of phenomena, but simply to represent them. In the best-case scenario, theories are able to order and classify what is decisive for their predictive capacity (Duhem 1908, 1914).