Not to converse with a man worthy of conversation is to waste the man. To converse with a man not worthy of conversation is to waste words. The wise waste neither men nor words.
These are the four abuses: desire to succeed in order to make oneself famous; taking credit for the labors of others; refusal to correct one's errors despite advice; refusal to change one's ideas despite warnings.
Listen widely to remove your doubts and be careful when speaking about the rest and your mistakes will be few. See much and get rid of what is dangerous and be careful in acting on the rest and your causes for regret will be few. Speaking without fault, acting without causing regret: 'upgrading' consists in this.