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.
All is the Self or Brahman. The saint, the sinner, the lamb, the tiger, even the murderer, as far as they have any reality, can be nothing else, because there is nothing else.
-Swami Vivekananda