Gigni de nihilo nihil, in nihilum nil posse reverti, are two propositions which the ancients connected inseparably, and which are now sometimes separated only out of misunderstanding, be cause one imagines that they pertain to things in themselves, and that the former would be opposed to the dependence of the world on a supreme cause (even as far as its substance is concerned); but this worry is unnecessary, for here the issue is only appearances in the field of ex perience, the unity of which would never be possible if we were to allow new things (as far as their substance is concerned) to arise.