Although most friendships that exist do not merit the name, we can nevertheless make use of them in accordance with our needs, as a kind of commercial venture based on uncertain foundations and in which we are very often deceived.

Criticism should awaken our attention, not inflame our anger. We should listen to, and not flee from, those who contradict us. Truth should be our cause, no matter in what manner it comes to us.

Virtue is not always where it seems to be. People sometimes acknowledge favors only to maintain their reputations, and to make themselves more impudently ungrateful for favors that they do not wish to acknowledge.

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.

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.

When people reproach us, they only increase their own failings even as they are disclaiming them.

All the great amusements are dangerous for the Christian life.