METAPHYSICS Scotus, as we have just seen, adds an extra metaphysical item to the apparatus employed by Aquinas Suarez, in his turn, adds an extra item of his own In Peter we have not just the matter and form which all followers of Aristotle accepted, and not just the individuating element that Scotists accepted, but an extra thing, that makes Peter a substance and not an accident Subsistence, the form of existence peculiar to substance as opposed to accident, adds to an individuated essence a mode, and there is a special form of composition which is that of mode-plus-thing-modiWed Suarez employed his notion of mode in an attempt to illuminate the diVerence between a soul existing embodied and a soul existing in separation after death But his new terminology was to be widely employed, and made popular, especially by Descartes Descartes on Eternal Truths Descartes took over many of the technical terms of scholastic metaphysics—substance, mode, form, essence, and so on—but used many of them in novel ways His most important innovation in metaphysics was one that was not fully spelt out in his published works and only became clear when his copious correspondence was made public after his death This was his doctrine of the creation of eternal truths In 1630, when he was completing his treatise The World, Descartes wrote to Mersenne: The mathematical truths that you call eternal have been laid down by God and depend on him entirely as much as all other creatures Please not hesitate to assert and proclaim everywhere that it is God who has laid down these laws in nature just as a king lays down laws in his kingdom (AT I 135; CSMK III 23) As for the eternal truths, I say once more that they are true or possible only because God knows them as true or possible They are not known as true by God in any way which would imply that they are true independently of Him In God willing and knowing are a single thing, in such a way that by the very fact of willing something He knows it, and it is only for this reason that such a thing is true (AT I.147; CSMK III 13) It was a new departure to say that the truths of logic and mathematics depended upon the will of God Scholastic philosophers agreed that they were dependent on God, but dependent on his essence, not on his will: 184