 Leibniz’s criticisms of the Newtonians were not restricted to questions about the nature of space and time; he also revived his old complaint—one shared by Huygens, as we have seen above—that Newton’s physical theory commits him to the possibility, if not to the reality, of action at a distance among the planetary bodies. In one passage in his fourth letter, for instance, Leibniz writes (Clarke and Leibniz 1717: L 4: 45):