 As McGuire (1970b: 182) points out “Newton did not see any dichotomy in method between that used in the Principia and that found in the Opticks”. But even if he considered his methodology fundamentally the same in both works, and he treated mathematical and experimental analyses as contributing to inquiry in the same manner, this was perceived differently by subsequent generations. In Query 31 Newton himself introduces two different ways of analysis that “may proceed from compounds to ingredients, and from motions to the forces producing them” (Opticks, Query 31 added in 1718, Newton 2004: 139; for a discussion see e.g. Ducheyne 2012; Demeter 2016): the first way allows for a qualitative analysis that does not require the centrality of a mathematical framework of analysis. The crucial element is indeed common to their methodology, namely the idea of causal analysis—this is the core of Newtonian analysis, and these are the terms in which Colin Maclaurin (1775: 8–10) introduces the Newtonian method to his contemporaries. Nevertheless, it is immediately clear from this passage that an analysis “from compounds to ingredients” must proceed differently and find different causes from an analysis “from motions to the forces producing them”: they will be different with respect to both the method of analysis, and the nature of the causes that can be so analysed.