Of all human studies, the study of wisdom is the most complete, most sublime, most useful, and most joyful:
Most complete because, inasmuch as man gives himself to the study of wisdom, so much does he have already some part of true beatitude, so that the wise man says, "Blessed the man who continues in wisdom" (Sir 14:22).
And it is most sublime because through this, man preeminently approaches to the divine likeness, who "made everything through wisdom" (Ps 103:24), in that, because likeness is the cause of love, the study of wisdom preeminently unites with God through friendship. Thus Wis 7:14 says that wisdom "is an infinite treasury to men, of a sort that those who use are made participants in friendship with God."
And it is most useful because through this wisdom we come to the kingdom of immortality: "Craving for wisdom leads to the perpetual kingdom" (Wis 6:21).
And it is most joyful because "her company has no harshness, nor her banquet any sorrow, but gladness and delight" (Wis 7:16).
[Thomas Aquinas, Summa Contra Gentiles 1.2.1, my rough translation. Studium could also be translated as 'pursuit', so one could substitute that for 'study' at any point here. The point of the 'most complete' is that, as the pursuit of wisdom already participates in beatitude, and beatitude or happiness lacking nothing is the ultimate end and goal of all human pursuits, there is nothing in any pursuit it does not in some way cover. Thus the honest seeker of wisdom, to the extent that he or she actually seeks wisdom, is fulfilled as a human being (blessed), a friend of God, is preparing for an inexhaustible reward, and is already in the process of achieving what he or she loves (which is how Aquinas understands joy).
ADDED LATER: I suppose I should say something about the 'most'. The terms are actually comparative in form, not superlative. I've gone back and forth, but if one follows through the reasoning, the claim is that the pursuit of wisdom is more complete, sublime, useful, and joyful than all (other) human pursuits. Thus, while the forms are comparative, the meaning is superlative.]
