Some appropriate quotes which I just throw out there, neither on offense nor defense:

Proverbs 12:1-2

"Whoever loves discipline loves knowledge, but he who hates correction is stupid."

Proverbs 13:15-17

"Every prudent man acts out of knowledge, but a fool exposes his folly."

(Reading and discussing the Bible is a good education, too -- kept me from building a kayak this past winter...)