Leibniz published in October 1684 the first printed exposition of differential calculus in the Acta Eruditorum of Leipzig. His notation — d for differentials, ∫ for integrals — proved so fertile that it became universally adopted and is the one used today. Although Newton had developed equivalent methods earlier, he had not published them; the priority dispute that followed was partly politically instrumentalized by the Royal Society. Modern historiography recognizes two independent, simultaneous developments.