"According to the Raja-Yogi, the external world is but the gross form of the internal, or subtle. The finer is always the cause, the grosser the effect. So the external world is the effect, the internal the cause. In the same way external forces are simply the grosser parts, of which the internal forces are the finer. The man who has discovered and learned how to manipulate the internal forces will get the whole of nature under his control. The Yogi proposes to himself no less a task than to master the whole universe, to control the whole of nature. He wants to arrive at the point where what we call "nature's laws" will have no influence over him, where he will be able to get beyond them all. He will be master of the whole of nature, internal and external. The progress and civilization of the human race simply mean controlling this nature."

- Swami Vivekananda, "Introductory" (Dec 14, 1895, New York Vedanta Society), Raja-Yoga, Complete Works: Vol 1