a self-sufficient nature. In other words, whatever lacks a necessary nature depends on something. But to lack a necessary nature is to have the real potential not to be actual. Therefore, from here, we may deduce the following principle: : Whatever is actual, but potentially not actual, depends on an actualizer. In other words, nothing can be (1) actual, (2) potentially not actual, yet (3) unactualized. I will examine the Principle of Actuality very closely in the next chapter.