Facing the Limits of Deductions from Phenomena: Newton’s Quest for a Mathematical-Demonstrative Optics

Abstract

In this chapter, I shall elaborate on the claims made by the late I. Bernard Cohen according to which Newton’s methodological ideal of “deducing causes from phenomena,” on which we have elaborated on in Chapters 2 and 3, was not equally attainable in the study of optical phenomena. If his suggestion is correct, then in The Opticks, the apex of his optical researches, which in fact contained a set of separate but interrelated theories, Newton failed to rigidly establish these theories in the same way as he had established the theory of universal gravitation in the Principia. By contrasting Newton’s methodology in the Principia, as previously characterized, to the method by which theoretical and causal conclusions are established in The Opticks, I shall attempt to explain why Newton was less successful to accommodate optical phenomena according to his own methodological desiderata of deducing causes from phenomena.