Friends will keep you sane, Love could fill your heart, A lover can warm your bed, But lonely is the soul without a mate.
David Pratt 

Friendship is like money, easier made than kept.
Samuel Butler 

Friendships are fragile things, and require as much handling as any other fragile and precious thing.
Randolph S. Bourne 

Good friends are good for your health.
Irwin Sarason 

I hate it in friends when they come too late to help.
Euripides 

If all men knew what others say of them, there would not be four friends in the world.
Blaise Pascal 

It destroys one's nerves to be amiable everyday to the same human being.
Benjamin Disraeli 

It is well, when judging a friend, to remember that he is judging you with the same godlike and superior impartiality.
Arnold Bennett 

Life is to be fortified by many friendships. To love and to be loved is the greatest happiness of existence.
Sydney Smith 

My heart has joined the Thousand, for my friend stopped running today.
Richard Adams  - Watership Down