When an opinionated person starts to challenge something, his mind shuts out all that could clear up the matter. The argument irritates him, however just it might be, and it seems that he is afraid of discovering the truth.

It is vain and useless to survey everything that goes on in the world if our study does not help us mend our ways.

It is base to take advantage of our rank or greatness by making fun of those placed beneath us in life.

It is such a great fault to talk too much that, in business and conversation, if what is good is also brief, it is doubly good, and one gains by brevity what one often loses by an excess of words.

Instead of taking care to acquaint ourselves with others, we only think of making ourselves known to them. It would be better to listen to other people in order to become enlightened rather than to speak so as to shine in front of them.

We must accustom ourselves to the follies of others and not be astonished at the foolishness that takes place in our presence.

In knowledge of human affairs, we should never allow our minds to be enslaved by others by subjecting ourselves to their whims. We must maintain freedom of thought, and never accept anything of purely human authority into our heads. When we are presented with a diversity of opinions, we must choose, if we can; if we cannot, we must remain in doubt.