"[1] Among all human pursuits, the pursuit of wisdom is more perfect, more noble, more useful, and more full of joy.
It is more perfect because, in so far as a man gives himself to the pursuit of wisdom, so far does he even now have some share in true beatitude. And so a wise man has said: 'Blessed is the man that shall continue in wisdom' (Sirach 14:22).
It is more noble because through this pursuit man especially approaches to a likeness to God Who 'made all things in wisdom' (Ps. 103:24). And since likeness is the cause of love, the pursuit of wisdom especially joins man to God in friendship. That is why it is said of wisdom that 'she is an infinite treasure to men! which they that use become the friends of God' (Wis. 7:14).
It is more useful because through wisdom we arrive at the kingdom of immortality. For 'the desire of wisdom leads to the everlasting kingdom' (Wis. 6:21).
It is more full of joy because 'her conversation has no bitterness, nor her company any tediousness, but joy and gladness' (Wis. 7:16).
[2] And so, in the name of the divine Mercy, I have the confidence to embark upon the work of a wise man, even though this may surpass my powers, and I have set myself the task of making known, as far as my limited powers will allow, the truth that the Catholic faith professes, and of setting aside the errors that are opposed to it. To use the words of Hilary: 'I am aware that I owe this to God as the chief duty of my life, that my every word and sense may speak of Him' [De Trinitate I, 37]."  (St. Thomas Aquinas, Contra Gentiles)