Pettiness of mind, ignorance and presumption are the cause of stubbornness, because stubborn people only want to believe what they themselves can imagine, and they can imagine very few things.

Nothing can tell us so much about the general lawlessness of humanity as a perfect acquaintance with our own immoderate behavior. If we would think over our own impulses, we would recognize in our own souls the guiding principle of all vices which we reproach in other people; and if it is not in our very actions, it will be present at least in our impulses. There is no malice that self-love will not offer to our spirits so that we may exploit any occasion, and there are few people virtuous enough not to be tempted.

Mean-spirited mediocrities, especially those with a smattering of learning, are the most likely to be opinionated. Only strong minds know how to correct their opinions and abandon a bad position.

There is a certain hidden mediocrity in those who are stationed above us in life, an ability to take liberties in their pursuit of pleasures and diversions, without injuring the honor and respect we owe to them.

We nearly always make ourselves masters of those whom we know well, because he who is thoroughly understood is in some sense subject to those who understand him.

There is always enough self-love hidden beneath the greatest devoutness to set limits on charity.

Everyone is so caught up in his own passions and interests that he always wants to talk about them without getting involved in the passions and interests of those to whom he speaks, although his listeners have the same need for others to listen to and help them.