DOI: 10.4324/9780415249126-Q075-1
Version: v1,  Published online: 1998
Retrieved June 20, 2018, from

Article Summary

Newton is best known for having invented the calculus and formulated the theory of universal gravity – the latter in his Principia, the single most important work in the transformation of natural philosophy into modern physical science. Yet he also made major discoveries in optics, and put no less effort into alchemy and theology than into mathematics and physics.

Throughout his career, Newton maintained a sharp distinction between conjectural hypotheses and experimentally established results. This distinction was central to his claim that the method by which conclusions about forces were inferred from phenomena in the Principia made it ’possible to argue more securely concerning the physical species, physical causes, and physical proportions of these forces’. The law of universal gravity that he argued for in this way nevertheless provoked strong opposition, especially from such leading figures on the Continent as Huygens and Leibniz: they protested that Newton was invoking an occult power of action-at-a-distance insofar as he was offering no contact mechanism by means of which forces of gravity could act. This opposition led him to a tighter, more emphatic presentation of his methodology in the second edition of the Principia, published twenty-six years after the first. The opposition to the theory of gravity faded during the fifty to seventy-five years after his death as it fulfilled its promise on such issues as the non-spherical shape of the earth, the precession of the equinoxes, comet trajectories (including the return of ’Halley’s Comet’ in 1758), the vagaries of lunar motion and other deviations from Keplerian motion. During this period the point mass mechanics of the Principia was extended to rigid bodies and fluids by such figures as Euler, forming what we know as ’Newtonian’ mechanics.

    Citing this article:
    Harper, William L. et al. Newton, Isaac (1642–1727), 1998, doi:10.4324/9780415249126-Q075-1. Routledge Encyclopedia of Philosophy, Taylor and Francis,
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