Only one who bursts with enthusiasm do I instruct; Only one who bubbles with excitement do I enlighten. If I hold up one corner and you do not come back to me with the other three, I do not continue the lesson.
Have you learned the lessons only of those who admired you, and were tender with you, and stood aside for you? Have you not learned great lessons from those who braced themselves against you, and disputed passage with you?
The poets aim is either to profit or to please, or to blend in one the delightful and the useful. Whatever the lesson you would convey, be brief, that your hearers may catch quickly what is said and faithfully retain it. Every superfluous word is spilled from the too-full memory.