The nineteenth-century Musar movement . . . was designed to help its followers work on their midot, or personal character traits. Disciples were trained to seek out opinions of teachers, colleagues, and friends to find ways to improve their character. It was unusual to be called a donkey, but disciples would very likely hear constructive suggestions on how levels of kindness, compassion, honesty, sincerity, and self-discipline could be raised. The recipients of such suggestions were trained to take them seriously. It was a mark of maturity, and even joy, to find new and better ways to improve personal character. All the better to serve God and other humans!

Dov Peretz Elkins, The Wisdom of Judaism