1st. Motive powers have no other formal ubication than that from which their exertions proceed; 2d. Motive powers are never distant from any matter; 3d. Motive powers are not merged or embedded in the matter to which they belong, but constitute a virtual sphere around it. That _actio in distans_ not only is possible, but is the only action possible with the material agents, has been proved in our preceding article. The embarrassment we experience in its explanation arises, not from our reason, but from our habit of relying too much on our imagination. “Imagination,” says S. Thomas, “cannot rise above space and time.” We depict to ourselves intellectual relations as local relations. The idea that a material point situated on the earth can exert its power on the polar star suggests to us the thought that the active power of that element must share the ubication of the polar star, and be locally present to it. Yet the true relation of the power to the star is not a local relation, and the exertion of the power is not terminated to the _place_ where the star is, but to the _star_ itself as to its proper subject; and therefore the relation is a relation of act to potency, not a relation of local presence. There is nothing local in the principle of activity, except the central point from which its action is directed; and there is nothing local in its action, except the direction from that central point to the subject to which the action is terminated. True it is that we speak of _a sphere_ of power, which seems to imply local relations. But such a sphere is not locally determined by the power, which has no ubication, but by the matter to which that power is to be applied. For the necessity of admitting a sphere of power arises from the fact that all the matter placed at equal distance from the centre of activity is equally acted on. It is only from matter to matter that distance can be conceived; and thus it is only from matter to matter, and not from matter to power, that the radius of a sphere can be traced. Abstract geometry deals with imaginary points, but physical geometry requires real points of matter.