/summa/FP/FPVII/FP_Q59:
In the next place we must treat of things concerning the will of the angels. In the first place we shall treat of the will itself; secondly, of its movement, which is love. Under the first heading there are four points of inquiry:
(1) Whether there is will in the angels?
(2) Whether the will of the angel is his nature, or his intellect?
(3) Is there free-will in the angels?
(4) Is there an irascible and a concupiscible appetite in them?