 That said, we shall also see that no one has yet discovered a fully satisfactory way of reconciling the numerous conflicting things that Leibniz says about motion. Some of these tensions can be put down simply to his changing his mind (see Cover and Hartz 1988 or Arthur 2013 for explications of how Leibniz’s views on space developed). However, we will concentrate on the fairly short period in the mid 1680–90s during which Leibniz developed his theory of mechanics, and was most concerned with its interpretation. We will supplement this discussion with the important remarks that he made in his Correspondence with  Samuel Clarke  around 30 years later (1715–1716); this discussion is broadly in line with the earlier period, and the intervening period is one in which he turned to other matters, rather than one in which his views on space were evolving dramatically.