 Despite Leibniz’s (and Huygens’s) criticisms of his theory of gravity in particular, and his methods in natural philosophy in general, Newton stuck to his guns. Nearly twenty years after their illuminating exchange in 1693, Leibniz and Newton narrowly missed a second opportunity to discuss their philosophical differences directly. In May of 1712, Leibniz published a letter to Nicholas Hartsoeker that was highly critical of the Newtonians; it was published in English translation in the Memoirs of Literature, a journal to which Roger Cotes, the editor of the Principia’s second edition, held a subscription (Newton 2004: 109). After Cotes brought Leibniz’s criticisms to Newton’s attention—especially the claim that the Principia renders gravitation a “perpetual miracle” because it does not specify the physical mechanism underlying it—Newton wrote an intriguing, but only posthumously published, rebuttal. Here is part of Newton’s paraphrase of Leibniz’s original letter: