Swami Vivekananda stressed on the positive attitudes of life- love, harmony, service and the like. Some of these concepts find echo in an emerging trend of psychological studies called Positive Psychology. In fact, most of these traits are considered as marks of spiritual wisdom.
Bless people when the revile you. Think how much good they are doing by helping to stamp out the false ego. Hold fast to the Atman, think only pure thoughts, and you will accomplish more than a regiment of mere preachers.
-Swami Vivekananda