"Leibnitz played an important role, and was better at tooting his own horn, and publishing, but Newton was the one who came up with the idea."
Maybe in the comic book version. But the idea had been around for centuries, probably back to the Egyptians. The Greek paradox of Achilles and the Hare (and the numerous variations) speaks to it.
It was very much a group effort. There was a group of Englishmen who really got it going, in the mid-1600s. Then Newton and Leibnitz (working entirely independently, but parallel) came up with some major advances.
But it really took a couple guys even after them (like Cauchy) to polish the calculus into what we know today.
Newton related his ideas to Leibnitz in letters. Leibnitz developed the ideas, and published, but neglected to give Newton proper credit. That was the source of the conflict.
Thanks. I thought calculus went as far back as the Egyptians as well. Wasn't trigonometry developed around that time as well?
Actually, relativity was pretty much a group effort as well. Einstein put the icing on the cake.
The concept of infinitesimal and infinitely large values had of course been around (Archimedes is the best example) but not the idea of ratios of such quantities limiting to a fixed quantity - which is the essence of calculus. Also the method of fluxions wasn't a group effort. Newton by in large developed and kept it to himself. That was the problem!