Let the wise guard their thoughts, which are difficult to perceive, extremely subtle, and wander at will. Thought which is well guarded is the bearer of happiness.
Happiness arises as a result of different causes and conditions. If you harm someone out of anger, you may feel some superficial satisfaction, but deep down you know it was wrong. Your confidence will be undermined. However, if you have an altruistic attitude, you’ll feel comfortable and confident in the presence of others.
How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it, except the pleasure of seeing it.