What is Mussar?
Says Rabbeinu Yonah:
על כן אמר שלמה המלך עליו השלום (משלי א׳:ב׳) לדעת חכמה ומוסר להבין. פירושו - כשרון המעשה ועזיבת העבירות יקרא חכמה כענין שנאמר - (דברים ד׳:ו׳) כי היא חכמתם ובינתכם. ואחר שילמוד וידע המצות ומה הם העבירות צריך שילמוד גנות העבירות. וההפסד והאבדן הנמצא בהם להרחיק נפשו מהם. ולהוכיח לעצמו בזכרון העונשים וליסר זולתו. וזאת הידיעה תקרא מוסר ולמוכיחים ינעם ללמוד לדעת זאת: [שערי תשובה ג' ג']
Therefore King Solomon, peace be upon him, said (Proverbs 1:2), “For learning wisdom and reproof; for understanding.” Its explanation is [that] proper action and abandonment of sins is called wisdom, like the matter that is stated (Deuteronomy 4:6), “for that is your wisdom and your understanding.” But after he learns and know the commandments and what are the sins, he needs to study the disgrace of the sins, and the damage and the loss that comes with them - in order to distance his soul from them; to reprimand himself by remembering the punishments and to reprove others. And this knowledge is called reproof (mussar); and it is pleasant for those that give rebuke to study this.
Chochma is knowing the difference between right and wrong. But that is NOT ENOUGH!! So I know that something is wrong - but I feel like doing it. It is the right thing to do but I don't feel like doing it!!! In our culture people generally know the difference between right and wrong and yet see what our world looks like!!
We have to know what harm aveiros do! It destroys the world and is SELF-DESTRUCTIVE as well, as Rabbeinu Yonah makes clear. Part of the "deal" is "ליסר זולתו" - to give others Mussar. By golly, if you see someone crossing the street and see a car speedily hurtling towards the person and he doesn't notice - won't you cry out and save him??! Of course you would. So when you learn how much harm aveiros do, you will also spread the word.
