All forms of concentration practiced at the mental level, whether intellectual, philosophical, aesthetic, emotional, or ethical have their value for preparing the mind for the yet greater forms of concentration that can only occur in a quiet, stable and calm mental space. Sri Aurobindo observes: “…and at the end or in their highest intensities they may and do lead first to an intellectual, then to a reflective perception of the divine Reality which may culminate in a sort of preliminary identification with it. But all this cannot go beyond a certain point.” All of these forms of focus and concentration are inherently limited by the mental consciousness and its separate and fragmented awareness, and they cannot be sustained for long before being diverted or distracted as new input enters into the mental space.
This brings us to the yogic methods which operate on a different basis, and thus make possible the additional development that goes beyond the mental limitations: “The systemic purification of the whole being for an integral reflection and taking in of the divine reality can only be done by the special methods of Yoga. Its absolute concentration has to take the place of the dispersed concentrations of the lower knowledge; the vague and ineffective identification which is all the lower knowledge can bring, has to be replaced by the complete, intimate, imperative and living union which Yoga brings.”
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 25, The Higher and the Lower Knowledge, pg. 495