Again, therefore, that we may return to the proposed object of investigation, how can a self-motive nature of this kind, which is mingled with the alter-motive, be the first principle of things? For it neither subsists from itself, nor does it in reality perfect itself; but it requires a certain other nature, both for its subsistence and perfection: and prior to it is that which is truly self-moved. Is therefore that which is properly self-moved the principle, and is it indigent of no form more excellent than itself?