Love is the supreme positive emotion, the one that encompasses all others. It is the feeling of positive resonance that you experience when you connect deeply with another person.
The more you experience positive emotions, the more open you become. The more open you are, the more you see. The more you see, the more you can do. The more you can do, the more you can grow.
People who learn to control inner experience will be able to determine the quality of their lives, which is as close as any of us can come to being happy.