As an introduction to Catholic ethics, I really enjoy this lecture. Topics covered include the human will, cardinal virtue, the distinction between moral and intellectual virtues, the struggle with passions, and also the Golden Mean. In particular, pay attention to the segment that begins shortly after the half-hour mark. Any virtue can become vicious if it is not balanced with all other virtues. Generosity, as charity, can quickly act viciously to one's own well-being such that it compromises your ability to approach all other forms of virtue, hence, the Golden Mean. The picture this creates is like a kind of dynamic stability, where one cannot perfect any virtue individually where he is not effecting the perfection of all other virtues - to consummate one, is to consummate all. Virtue involves skill and intellect. The matter is not simply a case of adhering to arbitrary rule-sets; rather, these are a perfection of habits which are necessary to a person's ability to grow, to adapt, to become more skilled, more attractive...really, more like the ideal human, more like Christ, more like God. Virtue is what balances the order of nature with the order of grace, or in other words, the animal with the Man.