The mind thinks of the self as separate, the heart knows better. As one great Indian master, Sri Nisargatta, put it, "The mind creates the abyss, and the heart crosses it."
~ from A PATH WITH HEART by Jack Kornfield
I have found that the greatest degree of inner tranquility comes from the development of love and compassion. The more we care for the happiness of others, the greater is our own sense of well-being. Cultivating a close, warmhearted feeling for others automatically puts the mind at ease.