  Le Grand was one of the few Cartesians to defend Descartes’s doctrine of the creation of essences and eternal truths. The thesis is that God is the efficient cause of all things, both actual and possible, including all the truths we call eternal, “In like manner as a king is the maker of all laws in his kingdom. For all these truths are inborn in us from him; as a king also would have them so in his subjects, if he had power enough to write his laws in their hearts.” (1694, p. 63)  The main worry that critics, like Malebranche, had of this doctrine was that it would remove any necessary foundation for the propositions of science and theology, making them contingent and uncertain. To answer this worry, Le Grand added that there is one important difference between kings and God in the way they set down their laws, “A king can change his laws because his will is changeable, but God’s will is unchangeable, for it is His perfection to be invariable in manner” (1694, p. 63). In this way, Le Grand attempted to account for the dependence of all things on God’s will, while at the same time accounting for the immutable foundation of the truths of natural philosophy.