When German philosopher Gottfried Leibniz published an important mathematical paper, it was the beginning of a lifelong feud between the two men.
Leibniz, one of Europe’s most prominent philosophers, had set his mind to one of the trickiest problems in mathematics – the way equations could describe the physical world. Like Newton, he created a new theory of calculus. However, Newton claimed he'd done the same work 20 years before and that Leibniz had stolen his ideas. But the secretive Newton hadn't published his work and had to hastily return to his old notes so the world could see his workings .