The correct statement about the development of Newton's theory of universal gravitation is: "Isaac Newton described the existence of gravitational force mathematically, but he built upon the ideas of other scientists before him."
This is accurate as Newton's work was influenced by the earlier contributions of scientists like Johannes Kepler, who formulated the laws of planetary motion, and Galileo, who studied the mechanics of motion. Newton's formulation of gravity mathematically synthesized these ideas and added his own insights.