With an absurd oversimplification, the 'invention' of the calculus is sometimes ascribed to two men, Newton and Leibniz. In reality, the calculus is the product of a long evolution that was neither initiated nor terminated by Newton and Leibniz, but in which both played a decisive part.
Richard Courant, Herbert Robbins (1979). “What is mathematics?: an elementary approach to ideas and methods”, Oxford University Press, USA
