  Leibniz's account of the pre-established harmony of mind and body is part of a more general position in his metaphysics: the existence of parallel modes of explanation. As we saw above, Leibniz believes that the mind will act according to its laws and the body according to its laws and the two will be in harmony. But Leibniz also believes that the mind or soul operates for particular ends and that therefore its actions are explicable in terms of final causes, whereas the actions of the body, purely instances of matter in motion according to the claims of the mechanical philosophy, are to be explained in terms of efficient causes. As he puts it in the Monadology §§79 and 81,