Gravity is only the bark of wisdom's tree; but it preserves it.
Even four harnessed horses cannot bring imprudent words back into the mouth.
Don't do unto others what you don't want done unto you.
A scholar who loves comfort is not fit to be called a scholar.
Those who understand a thing are not equal to those who are fond of it, and those who are fond of it are not equal to those who delight in it.
Knowledge is merely brilliance in organization of ideas and not wisdom. The truly wise person goes beyond knowledge.