We next consider how one creature moves another. This consideration will be threefold: (1) How the angels move, who are purely spiritual creatures; (2) How bodies move; (3) How man moves, who is composed of a spiritual and a corporeal nature.

Concerning the first point, there are three things to be considered: (1) How an angel acts on an angel; (2) How an angel acts on a corporeal nature; (3) How an angel acts on man.

The first of these raises the question of the enlightenment and speech of the angels; and of their mutual coordination, both of the good and of the bad angels.

Concerning their enlightenment there are four points of inquiry:

(1) Whether one angel moves the intellect of another by enlightenment?

(2) Whether one angel moves the will of another?

(3) Whether an inferior angel can enlighten a superior angel?

(4) Whether a superior angel enlightens an inferior angel in all that he knows himself?