A man who has committed a mistake and doesn't correct it, is committing another mistake.
-Confucius
A concurring opinion:
All men can make mistakes; but, once mistaken, a man is no longer stupid or accursed who, having fallen on ill, tries to cure that ill, not taking a fine undeviating stand. It is obstinacy that convicts of folly.
Sophocles, Antigone
Every month on the month, Less Wrong has a thread where we post Deep Wisdom from the Masters. I saw that nobody did this yet for December for some reason, so I figured I could do it myself.
* Please post all quotes separately, so that they can be voted up/down separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
* "Do not quote yourself." --Tiiba
* Do not quote comments/posts on LW/OB. That's like shooting fish in a barrel. :)
* No more than 5 quotes per person per monthly thread, please.