Sri Aurobindo's Conversations with Pavitra. Part 12. Two Parts of the Mind

Sri Aurobindo: In the first analysis, the mind is divided into two parts: one, whose movements are aroused by Nature; the other which shares the nature of the Purusha and remains immobile. Sri Aurobindo: It is now necessary to extend the power of this immobile part to remain the witness of the changes of the other. Thought will seem to occur in front of it, and it will become aware that it is universal Nature which raises the play of thoughts. One must go towards this universalization. Thoughts will come from outside and you will see them taking shape in you. You will also experience that you have power over them: you will be able to make a choice, refuse a movement, etc. This is the beginning of mastery.