Various systems of spiritual discipline and liberation from the senses. "Yoga" is a Sanskrit term derived from the root yug, "to harness horses to a chariot." In yoga one seeks to become bound to divine reality. Yoga has been developed into a philosophy, but its origins and essence are nonintellectual and entirely experiential. It is meaningful only if practiced. In yoga, the search for the mystery of the universe is undertaken in a search for one's own true self. There are many different types of yoga, each of which is based on a specific path of liberation, such as physical action, meditation, concentration, mantras, knowledge, sexual energy, and so on: Bhakti Yoga, Hatha Yoga, Jnana Yoga, Mantra Yoga, Raja Yoga, Tantric Yoga - these are just a sampling of some of the main paths. Yoga was exported westward first by the Sufis, between 1200 and 1700, but never reached Europe. That was accomplished largely through British colonialism. Beginning in the nineteenth century, major influences on the spread of yoga west were the Theosophical Society and various Indian mystics, among them Ramakrishna, Aurobindo and Yogananda.