Be courteous to all, but intimate with few, and let those few be well tried before you give them your confidence.
intimate, courteous, friendship
A true friend freely, advises justly, assists readily, adventures boldly, takes all patiently, defends courageously, and continues a friend unchangeably.
It is important to our friends to believe that we are unreservedly frank with them, and important to friendship that we are not.
There are no rules for friendship. It must be left to itself. We cannot force it any more than love.
FRIENDSHIP, THERE ARE NO RULES FOR FRIENDSHIP
Friendship is a strong and habitual inclination in two persons to promote the good and happiness of one another.