Journal of the History of Philosophy

1. introduction¹

ernan mcmullin once remarked that, although the “avowedly tentative form” of the Queries “marks them off from the rest of Newton’s published work,” they are “the most significant source, perhaps, for the most general categories of matter and action that informed his research.”² The Queries (or Quaestiones), which Newton inserted at the very end of the third book of the Opticks³ or its Latin rendition, Optice,⁴ constitute that part of his optical magnum opus which he reworked and augmented the most—especially between 1704 and 1717. While the main text of the Opticks itself underwent only minor changes and even fewer additions,⁵ the [End Page 675] contrary holds for the Queries. Whereas the Queries in the first edition of the Opticks (1704) contained 16 rather short queries or a modest 6 pages of text,⁶ its third edition (1721), of which the text was left untouched in the posthumously published edition (1730), contained 31 oftentimes elaborate queries or no less than 70 pages of text.⁷ Such significant proliferation of words surely merits our attention. The purpose of these queries, which Newton inserted after having pointed out that he had “not finished this part of my Design [i.e. the third book of the Opticks, which addressed diffraction, or as Newton called it: ‘infiexion’],” was to stimulate “a further search to be made by others.”⁸ In manuscript material composed later, he commented as follows on the purpose of the Queries: “these things I only hint as Quæres without asserting any thing.”⁹ Accordingly, the queries that he introduced were only “hints to be examined & improved by the further experiments & observations of such as are curious ↓inquisitive↓.”¹⁰ In Queries 1 to 5 in the first edition of the Opticks, he raised a number of questions that were related to diffraction. In the remainder of the Queries, he launched questions that were related to other domains: Queries 6–11 were related to heat and fire, Queries 12, 15, and 16 to visual perception, and Queries 13 and 14 to the analogy between sound and color. Two years later, in Optice (1706), which was translated by Samuel Clarke, Newton added 7 additional quaestiones:¹¹ Quaestiones 17 and 18 dealt with the double refraction of “Island Crystal,” Quaestiones 19–22 hinted at the plausibility of a corpuscular account of light, and the long concluding Quaestio 23, that is, the precursor of what would become Query 31 in the final edition of the Opticks, addressed the “virtues, powers, or forces [virtutes, potentias, sive vires]” by which the particles of bodies act upon one another at a distance (in Latin: per interjectum aliquod intervallum).¹² In Quaestio 20, he made public his views on the gravitational ether for the first time.¹³ At the same time, he added some theological excerpts in which he argued that natural philosophy will lead to “the primary Cause [i.e. God] itself [ad ipsam … Causam primam]” and that it will teach us to worship of “our true and most generous Author [verus noster & beneficentissimus Author].”¹⁴ [End Page 676] Now, at this point, the Queries or Quaestiones began to serve a dual purpose: on the one hand, they continued to put, in the spirit of the Queries of the first edition of the Opticks, certain topics on the agenda of future experimental-philosophical investigation; at the same time, however, they served the theological agenda which he cherished and gradually sought to make public after the appearance of the first edition of the Opticks. In the 1717 edition of the Opticks, which was reissued a year later, he inserted eight extra queries between what had been Quaestiones 16 and 17 in Optice (1706),¹⁵ and, additionally, he extended Queries 8, 11, 16, and 31.¹⁶ Queries 17–24 in Opticks (1717–18) discussed different sorts of ethers (the optical ether, the gravitational ether, and the ether potentially involved in acts of perception...