Letter 76 — On Learning Wisdom in Old Age (§19)

“Therefore, if he is determined invariably to follow that which is honourable, invariably to avoid baseness, and in every act of his life to have regard for these two things, deeming nothing else good except that which is honourable, and nothing else bad except that which is base; if virtue alone is unperverted in him and by itself keeps its even course, then virtue is that man’s only good, and nothing can thenceforth happen to it which may make it anything else than good. It has escaped all risk of change; folly may creep upwards towards wisdom, but wisdom never slips back into folly.”