by certain exercises, prescribed by Rāja Yoga, one can make his breathing slow and thereby diminish the speed of the thought-currents. During these breathing exercises, the mind is concentrated upon God or the Divine Idea, or some mystic words expressive of the Deity. This lessens the activity of the mind which then gradually experiences a calmness unfelt before, a calmness which in itself is a happiness which no form of enjoyment of material pleasure can afford. Calmness of mind develops into harmony, the result of the expression of the Sattwa attribute. There are five kinds of mental states: Murha, Khipta, Bikhipta, Ekāgra, and Samādhi. The Murha, ruled by predominant Tama, is generally attracted to evil objects owing to lack of discrimination. Khipta flits from one object to another in search of pleasure. It is ruled by predominant Rāja, so is ever active and never satisfied. The Bikhipta mental state, ruled by the equal combination of the three attributes, is generally like Khipta, but at times fixes its attention inwards though for a short time only. When the Bikhipta is helped by the practice of concentration into the Ekāgra (one-pointed) state, then it is that harmony is brought about. When, by constant practice, the one-pointed mind becomes unwaveringly fixed on the Deity or the Idea of the Deity gained through the increasing illumination of the Sattwa, it enters into the Samādhi (Trance) state, the state of Absolute absorption into the Deity. The practice of the Rāja Yoga has been forbidden in the Shāstras in the Kali Yuga (Iron Age) because, in this age, excepting in rare cases, the human body is too weak and delicate to stand the hardships, psychic exertions and physical privations of its practices, and because an adept Yogi-Gooroo, without whose constant help in every detail of it no student can attain the highest result, is very hard to be found. Many who now practice it under inexperienced Gooroos in India meet early death or develop incurable diseases or even turn insane. A moderate amount of simple breathing exercises may not be so injurious or fatal, but too much of it or the practice of the advanced rules ought never to be attempted, especially in the West, where a proper Gooroo can never be found and where most people's nerves are generally shaky. Gnāna Yoga is an entirely mental process of Yoga, a process of discriminating between the Unsubstantial and the Substantial in Nature and concentrating upon the only Substantial Essence of things and gradually getting absolutely absorbed by it. The keeping up of this process of thought in an unbroken stream requires living a life of simplicity, solitude and renunciation. The life in which this thought-current becomes unbroken is the last life, last incarnation of that soul. It escapes rebirth for good for which it has worked for many incarnations. Its separate Ego is merged in the universal Ego and finally is lost in and becomes one with the One-without-a-Second.