Uncovering the Methodology of the Principia (I): The Phase of Model Construction

Abstract

In the editorial preface to the second edition of the Principia (1713), Roger Cotes observed that: There are some who do not like all this [Newtonian] celestial physics just because it seems to be in conflict with the doctrines of Descartes and seems scarcely capable of being reconciled with these doctrines. They are free to enjoy their own opinion, but they ought to act fairly and not to deny to others the same liberty that they demand for themselves. Therefore, we should be allowed to adhere to the Newtonian philosophy, which we consider truer, and to prefer causes proved by phenomena to causes imagined and not yet proved [Newtonianam itaque philosophiam, quæ nobis verior habetur, retinere & amplecti licebit, & causas sequi per phænomena comprobatas, potius quam fictas & nondum comprobatas]. It is the province of true philosophy to derive the natures of things from causes that truly exist [Ad veram philosophiam pertinet, rerum naturas ex causis vere existentibus derivare], and to seek those laws by which the supreme artificer willed to establish this most beautiful order of the world, not those laws by which he could have, had it so pleased him.