I found this beautiful letter written by John Steinbeck to his son, Thom, on "love."
"If you are in love, that's a good thing - - - that's about the best thing that can happen to anyone. There are several kinds of love. One is a selfish, mean, grasping egotistical thing which uses love for self-importance. This is the ugly crippling kind. The other is the out-pouring of everything good in you----kindness, consideration and respect---not only social respect of manners, but the greater respect which is recognition of another person as unique and valuable. The first kind can make you sick and small and weak but the second can release in you strength and courage and goodness and even wisdom you didn't know you had."