text: Reflect, therefore, on this, that the effect of wisdom is a joy that is unbroken and continuous. The mind of the wise man is like the ultra-lunar firmament; eternal calm pervades that region. You have, then, a reason for wishing to be wise, if the wise man is never deprived of joy. This joy springs only from the knowledge that you possess the virtues. None but the brave, the just, the self-restrained, can rejoice. And when you query: "What do you mean? Do not the foolish and the wicked also rejoice?" I reply, no more than lions who have caught their prey. When men have wearied themselves with wine and lust, when night fails them before their debauch is done, when the pleasures which they have heaped upon a body that is too small to hold them begin to fester, at such times they utter in their wretchedness those lines of Vergil: