This division is very significant and useful, if you can catch clearly hold of the root idea. Of course, looking at the thing from beginning to end, you will see Prana, the great Life, the great Self, always present in all, and you will see the envelopes, the bodies, the sheaths, present at the different stages, taking different forms; but from the standpoint of yogic practice, that is called Prana, or Self, with which the man identifies himself for the time, including every sheath of matter from which the man is unable to separate himself in consciousness. That unit, to the yogi, is the Self, so that it is a changing quantity. As he drops off one sheath after another and says: “That is not myself,” he is coming nearer and nearer to his highest point, to consciousness in a single film, in a single atom of matter, a Monad. For all practical purposes of Yoga, the man, the working, conscious man, is so much of him as he cannot separate from the matter enclosing him, or with which he is connected. Only that is body which the man is able to put aside and say: “This is not I, but mine.” We find we have a whole series of terms in Yoga which may be repeated over and over again. All the states of mind exist on every plane, says Vyasa, and this way of dealing with man enables the same significant words, as we shall see in a moment, to be used over and over again, with an ever subtler connotation; they all become relative, and are equally true at each stage of evolution. Now it is quite clear that, so far as many of us are concerned, the physical body is the only thing of which we can say: “It is not myself”; so that, in the practice of Yoga at first, for you, all the words that would be used in it to describe the states of consciousness, the states of mind, would deal with the waking consciousness in the body as the lowest state, and, rising up from that, all the words would be relative terms, implying a distinct and recognisable state of the mind in relation to that which is the lowest. In order to know how you shall begin to apply to yourselves the various terms used to describe the states of mind, you must carefully analyse your own consciousness, and find out how much of it is really consciousness, and how much is matter so closely appropriated that you cannot separate it from yourself. States of Mind Let us take it in detail. Four states of consciousness are spoken of amongst us. “Waking” consciousness or Jagrat; the “dream” consciousness, or Svapna; the “deep sleep” consciousness, or Sushupti; and the state beyond that, called Turiya[1] How are those related to the body? [1] It is impossible to avoid the use of these technical terms, even in an introduction to Yoga. There are no exact English equivalents, and they are no more troublesome to learn than any other technical psychological terms.