Is form a quality? No: form is a reason. Now what is constituted by (material) substance, and reason? (In the warm body) it is neither what burns, nor what is visible; it is quality. If, however, it be said that combustion is an act emanating from reason, that being hot and white are ACTUALITIES, we could not find anything to explain quality. (Ennead II,6 (17) 2)
The purpose of the preceding considerations was to determine the meaning of the statement that intelligibles are actual; to decide whether every intelligible exist only actually, or whether it be only an actuality; and third, how even up there in the intelligible, where all things are ACTUALITIES, there can also exist something potentially. If, then, in the intelligible world, there be no matter which might be called potential, if no being is to become something which it not yet is, nor transform itself, nor, while remaining what it is, beget something else, nor by altering, cause any substitution, then there could not be anything potential in this World of eternal essence outside of time. Let us now address the following question to those who admit the existence of matter, even in intelligible things: “How can we speak of matter in the intelligible world, if by virtue of this matter nothing exists potentially? For even if in the intelligible world matter existed otherwise than it does in the sense-world, still in every being would be the matter, the form and the compound which constitutes it.” They would answer that in intelligible things, what plays the part of matter is a form, and that the soul, by herself, is form; but, in relation to something else, is matter. Is the soul then potential in respect of this other thing? Hardly, for the soul possesses the form, and possesses it at present, without regard to the future, and she is divisible in form and matter only for reason; if she contain matter, it is only because thought conceives of her as double (by distinguishing form and matter in her). But these two things form a single nature, as Aristotle also says that his “quintessence” is immaterial. (Ennead V,5 (25) 3)
How might one apply actual existence to intelligible things? Each of them exists actually because it has received form, as the statue (the compound) exists actually, or rather, because it is a form, and because its essence is a perfect form. The intelligence does not pass from the potentiality of thinking to the actuality of thinking. Otherwise, it would imply an anterior intelligence which would not pass from potentiality to actuality, which would possess everything by itself; for what exists potentially implies another principle whose intervention brings it to actuality, so as to be something existing actually. A being is an actuality when it always is what it is, by itself. Therefore, all first principles are ACTUALITIES; for they possess all they should possess by themselves, eternally. Such is the state of the soul which is not in matter, but in the intelligible world. The soul which is in matter is another actuality; she is, for instance, the vegetative soul; for she is in actuality what she is. We shall, therefore, have to admit that (in the intelligible world) everything exists actually, and that thus everything is actuality, because it has rightly been said that intelligible nature is always awake, that it is a life, an excellent life, and that there on high all ACTUALITIES are perfect. Therefore, in the intelligible world, everything exists actually, and everything is actuality and life. The place of intelligible things is the place of life, the principle and source of the veritable soul, and of intelligence. (Ennead V,5 (25) 3)