'Nothing operates where it is not,' is the rejection of actio in distans. The axiom has been disputed, especially since the discovery of the law of gravitation. Presence has been distinguished into 'local' and 'virtual'; a distinction coming near to that conveyed by the two Latin verbs, adsum and intersum. Presence indeed is not easy to define. Does presence belong to the term whence action comes, or to the term whither it goes, or to both? e.g., is the sun in any sense present on the earth? The mind is present in the body: is it not present too, although with a different presence; in the fixed stars, when it thinks about them? The presence of God, as St Thomas well lays down (B. III, Chap. LXVIII), is best defined by His action. 'Where God acts, God is': that statement of the axiom is sufficient for the argument in this case.
Of God and His Creatures: 4.21