The mind has five stages, Patanjali tells us, and Vyasa comments that “these stages of mind are on every plane”.  The first stage is the stage in which the mind is flung about, the Kshipta stage; it is the butterfly mind, the early stage of humanity, or, in man, the mind of the child, darting constantly from one object to another.  It corresponds to activity on the physical plane.  The next is the confused stage, Mudha, equivalent to the stage of the youth, swayed by emotions, bewildered by them; he begins to feel he is ignorant—­a state beyond the fickleness of the child—­a characteristic state, corresponding to activity in the astral world.  Then comes the state of preoccupation, or infatuation, Vikshipta, the state of the man possessed by an idea—­love, ambition, or what not.  He is no longer a confused youth, but a man with a clear aim, and an idea possesses him.  It may be either the fixed idea of the madman, or the fixed idea which makes the hero or the saint; but in any case he is possessed by the idea.  The quality of the idea, its truth or falsehood, makes the difference between the maniac and the martyr.

Maniac or martyr, he is under the spell of a fixed idea.  No reasoning avails against it.  If he has assured himself that he is made of glass, no amount of argument will convince him to the contrary.  He will always regard himself as being as brittle as glass.  That is a fixed idea which is false.  But there is a fixed idea which makes the hero and the martyr.  For some great truth dearer than life is everything thrown aside.  He is possessed by it, dominated by it, and he goes to death gladly for it.  That state is said to be approaching Yoga, for such a man is becoming concentrated, even if only possessed by one idea.  This stage corresponds to activity on the lower mental plane.  Where the man possesses the idea, instead of being possessed by it, that one-pointed state of the mind, called Ekagrata in Sanskrit, is the fourth stage.  He is a mature man, ready for the true life.  When the man has gone through life dominated by one idea, then he is approaching Yoga; he is getting rid of the grip of the world, and is beyond its allurements.  But when he possesses that which before possessed him, then he has become fit for Yoga, and begins the training which makes his progress rapid.  This stage corresponds to activity on the higher mental plane.

Out of this fourth stage or Ekagrata, arises the fifth stage, Niruddha or Self-controlled.  When the man not only possesses one idea but, rising above all ideas, chooses as he wills, takes or does not take according to the illumined Will, then he is Self-controlled and can effectively practice Yoga.  This stage corresponds to activity on the buddhic plane.