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.
Do not go for glass beads leaving the mine of diamonds. This life is a great chance. What, seekest thou the pleasures of the world? He is the fountain of all bliss. See for the highest, aim at that highest, and you shall reach the highest.
-Swami Vivekananda