There are three friendships which are advantageous, and three which are injurious. Friendship with the upright; friendship with the sincere; and friendship with the man of much observation: these are advantageous. Friendship with the man of specious airs; friendship with the insinuatingly soft; and friendship with the glib-tongued: these are injurious.
I have never seen one who really loves goodness or one who really hates wickedness. One who really loves goodness will not place anything above it. One who really hates wickedness will practice goodness in such a way that wickedness will have no chance to get at him. Is there anyone who has devoted his whole strength to doing good for even as long as a single day? I have not seen anyone give up such an attempt because he had not the strength to go on. Perhaps there is such a case, but I have never seen it.
He who learns but does not think, is lost! He who thinks but does not learn is in great danger... Men of superior mind busy themselves first getting at the root of things; when they succeed, the right course is open to them.
At 15 I set my heart on learning; At 30 I firmly took my stand; At 40 I had no delusions; At 50 I knew the Mandate of Heaven; At 60 my ear was attuned; At 70 I followed my heart's desire without overstepping the boundaries of right.