A brief maxim about friendship is as follows:

If you want to gain the friendship of others, you must first show kindness to others. ——Emerson

Friendship is the spice and painkiller of life. ——Emerson

It is a kind of nature to tell others about oneself; therefore, it is a kind of education to take seriously what others tell you about themselves. ——Goethe

One should not interact with people who have been ruined by wealth--Marie Curie

Promise can certainly gain friendship, but it is actions that cultivate and maintain friendship. ——Feltham

All the glory and wealth in the world cannot be compared to a good friend. ——Voltaire

A true friend is one soul conceived in two bodies.

——Aristotle