Enchiridion X

X

Upon every accident, remember to turn toward yourself and inquire what faculty you have for its use. If you encounter a handsome person, you will find continence the faculty needed; if pain, then fortitude; if reviling, then patience. And when thus habituated, the phenomena of existence will not overwhelm you.

This is strongly Aristotelian: virtue is a state of character formed by habituated practice. At first it is difficult to do a frightening thing that duty may require; with practice it becomes ordinary to do it. That is the virtue of courage. The virtue of reacting calmly and appropriately when with a beautiful person is the same; so too with these other things.