I had always been told that Newton had invented calculus out of thin air in order to help him develop his theories of mechanics, yet after reading about the development of calculus in the seventeenth century in “A Concise History of Mathematics” by Dirk J. Struik that appears not to be so.

From my reading, it appears that a lot of the concepts in calculus were already up in the air, so to speak at the time, that Newton’s methods weren’t particularly rigorous and that his notation and choice of language were so cumbersome (“fluxions”, etc.) that they held up British mathematics for a while whereas the continent raced ahead using Leibniz’s notations (IIRC).

Is the role of Newton in the development of calculus overplayed by patriotic British historians / mathematicians?