The sixth consideration deals with Nature itself and so we must must now define Nature. But Nature is a difficult thing to define, even amongst the wise there was disagreement about which came first, God or Nature. For if Nature came first, then God must have been created, which he cannot have been. But if God came first, then Nature must have been created, for only if Nature can have been born can it really come into existence. But some wise men define Nature as the originator of fire, and it is through fire that it enters sensible matter to enable its reproduction. Indeed it is clear that all things are created principally by fire. But Plato defined Nature as the Will of God, and this is the definition that meets with the most approval amongst the philosophers, for the Will of God is complete Goodness in its entirety and is present in all things. His will is born from his Divinity, so that things may be as they are, as they have been and as they always will be, and that Nature may be proof against aging. Nature, sensation and the whole world contains this Nature within them, in fact every living thing contains it. For each sex is fulfilled through procreation and this joining of the two or, more accurately, this unity between them-which you may well call desire or love (or both) – is quite beyond our understanding, just as much as are desire and love. However if both God and Nature are considered to exist and since neither can come from the other (for it must be that which is born of the first comes second), neither God nor Nature can be considered as having been born. Plato was quite correct when he stated that Nature is the Will of God, for God has always willed and it is necessary that he does so, for this is the truest cause of all things. Since, if it is the Will of God, Nature cannot have been born, then neither it nor God can have been born, and thus we must understand that the nature of the Macrocosm beyond the Microcosm is not Nature at all but God. For this same Nature, by which the world exists, is the Will of God; but the art that pursues Nature (that is, the Will of God) is the true knowledge of the Microcosm, and of what must be done. For it is not Nature that carries the vitriol from the mountain into the furnace, or builds a fire beneath. The true concern of man, his true art, is to prepare and produce the Medicine. Every man who has known that this art is the only true one may then practise it faithfully. He who has learned may then assume control. But whoever tries his skill should take care that he does not sin against the Will of God or the Laws of Nature.