For thousands of years extraordinary and supernatural phenomena have been studied, investigated, and generalised, the whole ground of the religious faculties of man has been analysed, and the practical result is the science of Raja Yoga. In the modern times Swami Vivekananda has been the most authoritative oracle to propound this age-old science of God-realization. The main theme of the book is concentration of mind as a means to superconscious state. The first part of the book comprises several lectures to classes delivered by the Swami in New York. The second part is a rather free translation of the aphorisms of Patanjali, with a running commentary. This is a book invaluable for all the practitioners of meditation
After every happiness comes misery; they may be far apart or near. The more advanced the soul, the more quickly does one follow the other. What we want is neither happiness nor misery. Both make us forget our true nature; both are chains--one iron, one gold; behind both is the Atman, who knows neither happiness nor misery. These are states, and states must ever change; but the nature of the Atman is bliss, peace, unchanging. We have not to get it, we have it; only wash away the dross and see it.
-Swami Vivekananda