Mathematical Aspects of Quantum Field Theory,by E. de Faria and W. de Melo

The article Newton's Principle? (Speiser 1983) serves to propagate the view—long generally held but certainly erroneous—that the Principia (Cajori 1969) contains a proof that ‘all conic sections are solutions of Newton's] universal law of gravitation’ (p. 149). It stops short, however, of expressing the more extreme commonly held misapprehension that the Principia gives—as it fallaciously purports to do—an outline of a proof that inverse-square force implies conic-section orbit; for the article goes on to say that only Johann Bernoulli succeeded in proving that the conic sections are the only solutions.