Sri Aurobindo observes that the status of purity and that of concentration are necessary to one another. “Purity and concentration are indeed two aspects, feminine and masculine, passive and active, of the same status of being; purity is the condition in which concentration becomes entire, rightly effective, omnipotent; by concentration purity does its works and without it would only lead to a state of peaceful quiescence and eternal repose.”
By achieving the types of purity of the being that allow the higher understanding to operate in a clear and direct manner without dilution or admixture, we can bring about a state of concentration that is incredibly focused and powerful.
We also find that where the impurity yet exists, the diffuse and varied impulses, emotions, suggestions, desires, cravings, thoughts and wishes all seem to jostle around inside the being creating a chaotic and unruly environment where concentration is basically impossible. Sri Aurobindo notes that “impurity is a confusion of Dharmas, a lax, mixed and mutually entangled action of the different parts of the being; and this confusion proceeds from an absence of right concentration of its knowledge on its energies in the embodied Soul.”
“Equally, without purity the complete, equal, flexible concentration of the being in right thought, right will, right feeling or secure status of spiritual experience is not possible. Therefore the two must proceed together, each helping the victory of the other, until we arrive at that eternal calm fro which may proceed some partial image in the human being of the eternal, omnipotent and omniscient activity.’
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 4, Concentration, pg. 303