The forms of purification that are frequently the focus of human endeavor tend to focus on the moral and ethical nature, and the imperfections that arise in this aspect of life. Sri Aurobindo, however, treats this as a secondary symptom of deeper forms of impurity and imperfection. His prescription is to focus on these deeper levels and set them right, with the assurance that the outer being, including the vital being that is subject to the moral defects, will be set straight thereby.
Sri Aurobindo particularly identifies two forms of impurity upon which to fix the attention: “One is a defect born of the nature of our past evolution, which has been a nature of separative ignorance; this defect is a radically wrong and ignorant form given to the proper action of each part of our instrumental being.” This is caused by identification with the separative ego-sense rather than the divine standpoint of existence, and thereby treats the world as something external, to be seized, mastered and conquered for the benefit of the ego-sense.
“The other impurity is born of the successive process of an evolution, where life emerges in and depends on body, mind emerges in and depends on life in the body, supermind emerges in and lends itself to instead of governing mind, soul itself is apparent only as a circumstance of the bodily life of the mental being and veils up the spirit in the lower imperfections. This second defect of our nature is caused by this dependence of the higher on the lower parts; it is an immixture of functions by which the impure working of the lower instrument gets into the characteristic action of the higher function and gives to it an added imperfection of embarrassment, wrong direction and confusion.”
The lower instruments are generally unable to hold and express the hgreater light and force of the higher nature. We can see this, for example, when an individual has an inspiration. The inspiration tends to set off the mental process which chews on the concept, works to try to organize it and frame it within a normal method of understanding. While something of that higher inspiration clearly can come through, it has been veiled, watered down and covered up with mental conceptualization. The same thing may happen when an individual has an opening that brings forth an experience of divine delight or bliss. The body cannot hold this energy and may break down in certain ways. The mind becomes intoxicated with the energy and the vital being may actually twist this energy into its characteristic downward-flowing action rather than allowing itself to be uplifted.
The outer instruments act something like a “step-down transformer”, taking the higher energy that flows in and expressing it out in a much less powerful and direct state. When we start from the basis of acceptance of the idea of our separative existence, it becomes easy to misunderstand, misinterpret and confuse the sense of the higher knowledge and force when it wants to manifest. When we then also express them through the weakness of the outer instruments, we can see the causes of much of human misconception, distortion and confused effort. By solving these two defects, the seeker can bring about a much more potent action based on knowledge rather than ignorance.
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 5, The Instruments of the Spirit, pp. 618-619