Book Three — Providence, Chapter 80 — Summa Contra Gentiles
[1] Since bodily things are ruled by spiritual things, as we showed, and since there is an order of bodily things, the higher bodies must be ruled by the higher intellectual substances, while the lower bodies are ruled by the lower ones. Moreover, since the higher a substance is the more universal is its power, but the power of an intellectual substance is more universal than the power of a body, the higher intellectual substances, then, have powers incapable of functioning through bodily power, and so they are not united with bodies. But the lower ones have particular powers that are capable of functioning through certain bodily organs, and so they must be united with bodies.
[2] Now, as the higher intellectual substances are more universal in their power, they are also more perfectly receptive of divine control from Him, in the sense that they know the plan of this order down to its singular details because they receive it from God. However, this manifesting of the divine ordering stretches down by divine action to the last of the intellectual substances; as it is stated: “Is there any numbering of His soldiers? And upon whom shall not His light arise?” (Job 25:3). But the lower understandings do not receive it with such perfection that they are able to know through it the individual details which pertain to the order of providence, and which they are to execute. Rather, they know them in a general sort of way. The lower they are, the fewer details of the divine order do they receive through the first illumination which they get from the divine source. So much so, that the human understanding, which is the lowest according to natural knowledge, gets a knowledge of certain most universal items only.
[3] And thus, the higher intellectual substances obtain immediately from God a perfect knowledge of the aforementioned order; and then, other lower substances must obtain this perfect knowledge through them, just as we said above that the student’s universal knowledge is brought to perfection by the knowledge of the teacher who knows in detail. Hence, Dionysius, speaking of the highest intellectual substances whom he calls the first hierarchy, that is, the sacred sovereignty, says: “they are not sanctified by other substances but they are immediately ranged about Himself by the Godhead and are conducted to the immaterial and invisible beauty, in so far as it is permitted, and to the knowable reasons for the divine workings.” And thus, through them, handsays, “those placed below in the ranks of the celestial essences are instructed.” In this way, then, the higher understandings receive a perfect knowledge from a higher source of knowledge.
[4] Moreover, in every arrangement of providence this ordering of effects is derived from the form of the agent, because the effect must proceed from the cause by virtue of a certain likeness. Now, the fact that an agent communicates a likeness of his form to his effects is due to some end. So, the first principle in providential arrangement is the end; the second is the form of the agent; and the third is the arrangement of the order of the effects. Therefore, the highest function in the order of understanding is for the rational nature of the order to be considered in relation to the end; and the second most important thing is to observe it in relation to the form; while the third thing is to know the arrangement of this order in itself, and not in a higher source. Thus, the art which considers the end is architectonic in relation to the one which considers the form, as the art of navigating a ship is to the art of making one; but the art which considers the form is architectonic in relation to the art which merely considers the orders of the motions that are ordered in terms of the form, as the art of shipbuilding orders the skill of the workmen.
[5] So, there is a definite order in those understandings which grasp immediately in God Himself a perfect knowledge of the order of divine providence. For the highest and first intellects perceive the plan of the providential order in the ultimate end itself, which is the divine goodness, and some of them do so more clearly than others. These are called Seraphim, meaning the “ardent” or “burning” ones, because the intensity of love or desire, which are functions concerned with the end, is customarily symbolized by fire. Thus Dionysius says that, as a result of this name of theirs, there is a suggestion of “their mobility in relation to the divine, a fervent and flexible mobility, and of their leading of lower things to God,” as to their end.
[6] The second type of understandings know the plan of providence perfectly in the divine form itself. These are called Cherubim, which means “fullness of knowledge.” Indeed, knowledge is made perfect through the form of the knowable object. Hence, Dionysius says that this way of naming them suggests that they are “capable of contemplating the first operative power of divine beauty.