The thing with Newton's Principia is that's an exposition of the laws of his dynamics using proofs from elementary geometry but no calculus as such.
Newton and Leibniz separately discovered calculus but the calculus they created had no rigorous basis - it took until the middle of 19th century to formulate the axiomatic system that calculus is framed in today.
So it's natural Newton would want to write his results in a form that was rigorous and unassailable. But this meant that, as Keynes says, the final form didn't bear a relationship to intuition it was taken from.
Newton and Leibniz separately discovered calculus but the calculus they created had no rigorous basis - it took until the middle of 19th century to formulate the axiomatic system that calculus is framed in today.
So it's natural Newton would want to write his results in a form that was rigorous and unassailable. But this meant that, as Keynes says, the final form didn't bear a relationship to intuition it was taken from.