Newton's propositions or comets: Steps in transition, 1681-84

Isaac Newton's closest approach to a system of the world in the critical pe riod 1681-84 is provided in a set of untitled propositions concerning comet s. They drastically revise his position maintained against Flamsteed in 168 1 and may signal his adoption of a single comet solution for the appearance s of 1680/1. Points of agreement and difference with the key pre-Principia texts of 1684-85 are analysed. He shows substantial control of the phenomen a of tails which change very little in mechanical detail throughout his sub sequent work. An emerging theory of gravitation brings planets, their satel lites, and comets under the same laws of motion. yet retains a celestial vo rtex and includes a singular preposition in lieu of the usual formulation o f Kepler's area law. The analysis raises questions on a number of issues of recent Newtonian scholarship ranging from his achievement following his co rrespondence with Robert Hooke in 1679 to his veneration of the wisdom of t he ancients.