I answer that, There exists in the angels a natural love, and a love of choice. Their natural love is the principle of their love of choice; because, what belongs to that which precedes, has always the nature of a principle. Wherefore, since nature is first in everything, what belongs to nature must be a principle in everything.
This is clearly evident in man, with respect to both his intellect and his will. For the intellect knows principles naturally; and from such knowledge in man comes the knowledge of conclusions, which are known by him not naturally, but by discovery, or by teaching. In like manner, the end acts in the will in the same way as the principle does in the intellect, as is laid down in Phys. ii, text. 89. Consequently the will tends naturally to its last end; for every man naturally wills happiness: and all other desires are caused by this natural desire; since whatever a man wills he wills on account of the end. Therefore the love of that good, which a man naturally wills as an end, is his natural love; but the love which comes of this, which is of something loved for the end's sake, is the love of choice.
There is however a difference on the part of the intellect and on the part of the will. Because, as was stated already (Question [59], Article [2]), the mind's knowledge is brought about by the inward presence of the known within the knower. It comes of the imperfection of man's intellectual nature that his mind does not simultaneously possess all things capable of being understood, but only a few things from which he is moved in a measure to grasp other things. The act of the appetitive faculty, on the contrary, follows the inclination of man towards things; some of which are good in themselves, and consequently are appetible in themselves; others being good only in relation to something else, and being appetible on account of something else. Consequently it does not argue imperfection in the person desiring, for him to seek one thing naturally as his end, and something else from choice as ordained to such end. Therefore, since the intellectual nature of the angels is perfect, only natural and not deductive knowledge is to be found in them, but there is to be found in them both natural love and love of choice.
In saying all this, we are passing over all that regards things which are above nature, since nature is not the sufficient principle thereof: but we shall speak of them later on (Question [62]).