Everything that we see, or imagine, or dream, we have to perceive in space. This is the ordinary space, called the Mahâkâsha, or elemental space. When a Yogi reads the thoughts of other men, or perceives supersensuous objects he sees them in another sort of space called the Chittâkâsha, the mental space. When perception has become objectless, and the soul shines in its own nature, it is called the Chidâkâsha, or knowledge space. When the Kundalini is aroused, and enters the canal of the Sushumna, all the perceptions are in the mental space. When it has reached that end of the canal which opens out into the brain, the objectless perception is in the knowledge space. Taking the analogy of electricity, we find that man can send a current only along a wire, but nature requires no wires to send her tremendous currents. This proves that the wire is not really necessary, but that only our inability to dispense with it compels us to use it.