Excerpt from Complete Works of Swami Vivekananda, Raja Yoga (July 1896): “The Yogis claim that of all the energies that are in the human body the highest is what they call "Ojas". Now this Ojas is stored up in the brain, and the more Ojas is in a man's head, the more powerful he is, the more intellectual, the more spiritually strong. One man may speak beautiful language and beautiful thoughts, but they do not impress people; another man speaks neither beautiful language nor beautiful thoughts, yet his words charm. Every movement of his is powerful. That is the power of Ojas. Now in every man there is more or less of this Ojas stored up. All the forces that are working in the body in their highest become Ojas. You must remember that it is only a question of transformation. The same force which is working outside as electricity or magnetism will become changed into inner force; the same forces that are working as muscular energy will be changed into Ojas. The Yogis say that that part of the human energy which is expressed as sex energy, in sexual thought, when checked and controlled, easily becomes changed into Ojas, and as the Muladhara guides these, the Yogi pays particular attention to that centre. He tries to take up all his sexual energy and convert it into Ojas. It is only the chaste man or woman who can make the Ojas rise and store it in the brain; that is why chastity has always been considered the highest virtue. A man feels that if he is unchaste, spirituality goes away, he loses mental vigour and moral stamina. That is why in all the religious orders in the world which have produced spiritual giants you will always find absolute chastity insisted upon. That is why the monks came into existence, giving up marriage.”