Summa contra Gentiles3.79 Chapter LXXIX. That the lower intellectual substances are ruled by the higher

Forasmuch as some intellectual creatures are higher than others, as we have shown;! the lower intellectual nature must needs be governed by the higher.

Again. The more universal powers move the particular powers, as already stated.? And the higher intellectual natures have more universal forms, as we have proved.?

Besides. The intellective faculty that is nearer to the principle is always found to be the ruler of the intellectual faculty that is more distant from the principle: this is evident both in speculative and in practical science. For the speculative science that receives its principles of demonstration from another, is said to be subalternate to it, and the practical science that is nearer to the end, which ts the principle in practical matters, is the master science in comparison with the more distant. Since then some intellectual substances are nearer to the first principle, namely God, as we have shown, they will be the rulers of the others.

Moreover. The higher intellectual substances receive the influence of divine wisdom more perfectly, since each one receives something according to its mode. Now all things are governed by divine wisdom, so that those which have the greater share of divine wisdom, govern those which have the smaller share. Therefore the lower intellectual substances are governed by the higher.

Wherefore the higher spirits are called both angels, inasmuch as they direct the lower spirits, by message as it were, for angels are called messengers; and ministers, forasmuch as by their operation they execute, even in corporeal things, the order of divine providence: because a minister is like an animate instrument according to the Philosopher.t This is what is said (Ps. ciii. 4): Who makest thy angels spirits: and thy ministers a burning fire.