It is easier to be a true friend than to know one. For how can you know whether one who smiles and takes your arm seeks foremost your welfare, or whether he has some other motive? You must know his hopes and dreams. You must know his ambitions and desires. A man may confuse a smile for friendship when its real meaning is that of oppression, or a cry for anger when it is a plea for help. No, friendship is not a simple thing to know. 

But to be a friend is no more than a choice. That is why we must each give friendship more often than we are certain to see it, for it is the only way that friendship will increase in the world.

From the Wisdom of Ashael

(Dreams and Shadows, The Aylosian Chronicles #1)