Tact is the knack of making a point without making an enemy.

Every aquarium will eventually leak.

There is a wisdom of the head, and... there is a wisdom of the heart.

Every intelligent individual wants to know what makes him tick, and yet is at once fascinated and frustrated by the fact that oneself is the most difficult of all things to know.

The heart has its reasons which reason knows not.

I've learned that people will forget what you said, people will forget what you did, but people will never forget how you made them feel.

Experience keeps a dear school, but fools will learn in no other.

Learned we may be with another man's learning: we can only be wise with wisdom of our own.

Property is surely a right of mankind as real as liberty.

To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

What can't be cured must be endured.

You cannot truly listen to anyone and do anything else at the same time.

Better mad with the rest of the world than wise alone.

The pendulum of the mind oscillates between sense and nonsense, not between right and wrong.

The difference between stupidity and genius is that genius has its limits.

If we don't believe in freedom of expression for people we despise, we don't believe in it at all.

I mistrust the judgement of every man in a case in which his own wishes are concerned.

Your reputation is in the hands of others. That's what the reputation is. You can't control that. The only thing you can control is your character.

A perfection of means, and confusion of aims, seems to be our main problem.

Medicine heals diseases of the body, wisdom frees the soul from passions.