The concentration called right knowledge is that which is followed by reasoning, discrimination bliss, unqualified egoism.
Samadhi is divided into two varieties. One is called the Samprajnâta, and the other the Asamprajnâta.
In the Samprajnata Samadhi come all the powers of controlling nature. It is of four varieties. The first variety is called the Savitarka, when the mind meditates upon an object again and again, by isolating it from other objects.
Again, in the very same meditation, when one struggles to take the elements out of time and space, and think of them as they are, it is called Nirvitarka, without question. When the meditation goes a step higher, and takes the Tanmatras as its object, and thinks of them as in time and space, it is called Savichâra, with discrimination; and when in the same meditation one eliminates time and space, and thinks of the fine elements as they are, it is called Nirvichâra, without discrimination. The next step is when the elements are given up, both gross and fine, and the object of meditation is the interior organ, the thinking organ. When the thinking organ is thought of as bereft of the qualities of activity and dullness, it is then called Sânanda, the blissful Samadhi. When the mind itself is the object of meditation, when meditation becomes very ripe and concentrated, when all ideas of the gross and fine materials are given up, when the Sattva state only of the Ego remains, but differentiated from all other objects, it is called Sâsmita Samadhi. The man who has attained to this has attained to what is called in the Vedas "bereft of body". He can think of himself as without his gross body; but he will have to think of himself as with a fine body. Those that in this state get merged in nature without attaining the goal are called Prakritilayas, but those who do not stop even there reach the goal, which is freedom.