Objection 1: It would seem that bodies do not obey the angels in local motion. For the local motion of natural bodies follows on their forms. But the angels do not cause the forms of natural bodies, as stated above (A). Therefore neither can they cause in them local motion.
Objection 2: Further, the Philosopher (Phys. viii, 7) proves that local motion is the first of all movements. But the angels cannot cause other movements by a formal change of the matter. Therefore neither can they cause local motion.
Objection 3: Further, the corporeal members obey the concept of the soul as regards local movement, as having in themselves some principle of life. In natural bodies, however, there is not vital principle. Therefore they do not obey the angels in local motion.
On the contrary, Augustine says (De Trin. iii, 8,9) that the angels use corporeal seed to produce certain effects. But they cannot do this without causing local movement. Therefore bodies obey them in local motion.
I answer that, As Dionysius says (Div. Nom. vii): |Divine wisdom has joined the ends of the first to the principles of the second.| Hence it is clear that the inferior nature at its highest point is in conjunction with superior nature. Now corporeal nature is below the spiritual nature. But among all corporeal movements the most perfect is local motion, as the Philosopher proves (Phys. viii, 7). The reason of this is that what is moved locally is not as such in potentiality to anything intrinsic, but only to something extrinsic -- -that is, to place. Therefore the corporeal nature has a natural aptitude to be moved immediately by the spiritual nature as regards place. Hence also the philosophers asserted that the supreme bodies are moved locally by the spiritual substances; whence we see that the soul moves the body first and chiefly by a local motion.
Reply to Objection 1: There are in bodies other local movements besides those which result from the forms; for instance, the ebb and flow of the sea does not follow from the substantial form of the water, but from the influence of the moon; and much more can local movements result from the power of spiritual substances.
Reply to Objection 2: The angels, by causing local motion, as the first motion, can thereby cause other movements; that is, by employing corporeal agents to produce these effects, as a workman employs fire to soften iron.
Reply to Objection 3: The power of an angel is not so limited as is the power of the soul. Hence the motive power of the soul is limited to the body united to it, which is vivified by it, and by which it can move other things. But an angel's power is not limited to any body; hence it can move locally bodies not joined to it.