To acknowledge our faults when we are blamed, is modesty; to discover them to one's friends in ingenuousness, is confidence; but to preach them to all the world, if one does not take care, is pride.
If I am walking with two other men, each of them will serve as my teacher. I will pick out the good points of the one and imitate them, and the bad points of the other and correct them in myself.
The superior man honors his virtuous nature, and maintains constant inquiry and study, seeking to carry it out to its breadth and greatness, so as to omit none of the more exquisite and minute points which it embraces, and to raise it to its greatest height and brilliancy.
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.
Therefore only through education does one come to be dissatisfied with his own knowledge, and only through teaching others does one come to realize the uncomfortable inadequacy of his knowledge. Being dissatisfied with his own knowledge, one then realizes that the trouble lies with himself, and realizing the uncomfortable inadequacy of his knowledger.