  Although some loose-ends continued to defy resolution until much later in the eighteenth century, by the early 1750s Newton's theory of gravity had become the accepted basis for ongoing research among almost everyone working in orbital astronomy. Clairaut's successful prediction of the month of return of Halley's comet at the end of this decade made a larger segment of the educated public aware of the extent to which empirical grounds for doubting Newton's theory of gravity had largely disappeared. Even so, one must still ask of anyone outside active research in gravitational astronomy just how aware they were of the developments from ongoing efforts when they made their various pronouncements about the standing of the science of the Principia among the community of researchers. The naivety of these pronouncements cuts both ways: on the one hand, they often reflected a bloated view of how secure Newton's theory was at the time, and, on the other, they often underestimated how strong the evidence favoring it had become. The upshot is a need to be attentive to the question of what anyone, even including Newton himself, had in mind when they spoke of the science of the Principia.