Jnana Yoga is the approach to spiritual enlightenment through discrimination and reason. There may be two people on this planet who can properly practice Jnana Yoga. Still, it is good to practice this yoga even a little.
Jnana Yoga makes strong use of the powers of the mind. It is the path of the philosopher who wants to go beyond the visible universe.
Shankara translated by Swami Prabhavananda and Christopher Isherwood
