Man is very well defended against himself... The actual fortress is inaccessible, even invisible to him, unless his friends and enemies play the traitor and conduct him in by a secret path.

Marriage was contrived for ordinary people, for people who are capable of neither great love nor great friendship, which is to say, for most people, but also for those exceptionally rare ones who are capable of love as well as of friendship.

It is not a lack of love, but a lack of friendship that makes unhappy marriages.

The best friend will probably acquire the best wife, because a good marriage is founded on the talent for friendship.

There is some self-interest behind every friendship. There is no friendship without self-interests. This is a bitter truth.

In friendship, as in love, we are often happier through our ignorance than our knowledge.