So, while neither he nor Leibnitz can be credited with coming up with that idea, without which calculus would've gone nowhere, Newton systemized it all and took it much further than anyone else had in the Principia.
Imagine if, instead of two people like Newton and Einstein coming along every thousand years, we had billions of them. I hope genetic engineering can give us that someday!
Too many cooks in the kitchen might not be a good thing...
Somebody has to drive garbage trucks, mop the auditorium floor, etc., and I gotta say I'm glad there's people around to do these jobs...
Pascal used them, although he did not publish that, and his notation was his own alone. The ancients used them, too, Achilles and the hare, the motion of the arrow both presenting problems some used to prove the impossibility of motion. Oddly, Achilles caught the hare and the arrow proved useful in practice anyway, which says something about the utility of philosophers when they are not driving trucks.