I answer that, As was stated above (A. 1) to enjoy is not the act of the power that achieves the end as executor, but of the power that commands the achievement; for it has been said to belong to the appetitive power. Now things void of reason have indeed a power of achieving an end by way of execution, as that by which a heavy body has a downward tendency, whereas a light body has an upward tendency. Yet the power of command in respect of the end is not in them, but in some higher nature, which moves all nature by its command, just as in things endowed with knowledge, the appetite moves the other powers to their acts. Wherefore it is clear that things void of knowledge, although they attain an end, have no enjoyment of the end: this is only for those that are endowed with knowledge.
Now knowledge of the end is twofold: perfect and imperfect. Perfect knowledge of the end, is that whereby not only is that known which is the end and the good, but also the universal formality of the end and the good; and such knowledge belongs to the rational nature alone. On the other hand, imperfect knowledge is that by which the end and the good are known in the particular. Such knowledge is in irrational animals: whose appetitive powers do not command with freedom, but are moved according to a natural instinct to whatever they apprehend. Consequently, enjoyment belongs to the rational nature, in a perfect degree; to irrational animals, imperfectly; to other creatures, not at all.
Reply Obj. 1: Augustine is speaking there of perfect enjoyment.
Reply Obj. 2: Enjoyment need not be of the last end simply; but of that which each one chooses for his last end.
Reply Obj. 3: The sensitive appetite follows some knowledge; not so the natural appetite, especially in things void of knowledge.
Reply Obj. 4: Augustine is speaking there of imperfect enjoyment. This is clear from his way of speaking: for he says that "it is not so absurd to suppose that even beasts enjoy," that is, as it would be, if one were to say that they "use." ________________________
THIRD ARTICLE [I-II, Q. 11, Art. 3]
Whether Enjoyment Is Only of the Last End?
Objection 1: It would seem that enjoyment is not only of the last end. For the Apostle says (Philem. 20): "Yea, brother, may I enjoy thee in the Lord." But it is evident that Paul had not placed his last end in a man. Therefore to enjoy is not only of the last end.
Obj. 2: Further, what we enjoy is the fruit. But the Apostle says
(Gal. 5:22): "The fruit of the Spirit is charity, joy, peace," and
other like things, which are not in the nature of the last end.
Therefore enjoyment is not only of the last end.