Way back then, calculus was a culture war battleground. Bishop Berkeley famously argued the foundations of calculus weren't any better that those of theology.

Way back then, calculus was a culture war battleground. Bishop Berkeley famously argued the foundations of calculus weren't any better that those of theology. This sort of thing motivated much work into shoring them up, getting rid of infinitesimals and the like (or, later, making infinitesimals rigorous in nonstandard analysis). https://en.wikipedia.org/wiki/The_Analyst https://en.wikipedia.org/wiki/The_Analyst