Book 4 — Concerning an IMMOVEABLE, and SELF-MOTIVE PRINCIPLE or CAUSE.

PROPOSITION XIV.

Every being is either immoveable, or moved; and if moved, it is either moved by itself, or by another.

In the first place if it is moved by itself, it is self-motive, but if by another, it is alter-motive (ἑτεροκίνητον.) Every being therefore, is either immoveable, or self-motive, or alter-motive. For it is necessary, that since there are alter-motive natures, there should be something immoveable, and between these, a self-motive nature. For if every thing alter-motive, when in motion is moved by another, motions are either performed in a circle, or in infinitum. But they can neither subsist in a circle, nor in infinitum, since all beings are terminated by a principle, and the motive nature, is more excellent than the thing moved. Something immoveable therefore will be the first mover. But if this be the case, it is necessary that there should be something self-motive. For should all things stand still, what will that be which is first moved? It cannot be the immoveable itself, for motion is not natural to this. Nor the alter-motive, for it is moved by another. It remains therefore that the self-motive, must be that which is first moved; since it is this which unites the alter-motive to the immoveable, existing as a medium, moving, and at the same time moved. For of those, the one moves alone, and the other is alone moved. Every being therefore, is either immoveable, or self-motive, or alter-motive.

COROLLARY.

From hence also it is evident, that of things which are moved, a self-motive nature is the first, but of things motive, an immoveable nature.