Full Idea
Newton showed that the apparently different kinds of processes of falling towards the earth and orbiting the sun are essentially the same.
Gist of Idea
Newton showed that falling to earth and orbiting the sun are essentially the same
Source
report of Isaac Newton (Principia Mathematica [1687]) by Brian Ellis - Scientific Essentialism 3.08
Book Reference
Ellis,Brian: 'Scientific Essentialism' [CUP 2007], p.125
A Reaction
I quote this to illustrate Newton's permanent achievement in science, in the face of a tendency to say that he was 'outmoded' by the advent of General Relativity. Newton wasn't interestingly wrong. He was very very right.