"Man is man so long as he is struggling to rise above nature, and this nature is both internal and external. Not only does it comprise the laws that govern the particles of matter outside us and in our bodies, but also the more subtle nature within, which is, in fact, the motive power governing the external. It is good and very grand to conquer external nature, but grander still to conquer our internal nature. It is grand and good to know the laws that govern the stars and planets; it is infinitely grander and better to know the laws that govern the passions, the feelings, the will, of mankind. This conquering of the inner man, understanding the secrets of the subtle workings that are within the human mind, and knowing its wonderful secrets, belong entirely to religion."

- Swami Vivekananda, "The Necessity of Religion" (June 7, 1896, Royal Institute of Painters, London), Jnana Yoga, Complete Works: Vol 2