Progress in Yoga, and in the development of consciousness, as in the general evolutionary movement, does not occur in a straight, undeviating, unbroken upward line. There may in fact be times when fast and effective progress is being made, and then a period of consolidation when the being feels like the inspiration or energy has disappeared or slackened, or even, periods of apparent retrogression where old habits and modes of being reassert themselves for a time. These periods may be quite lengthy, as evidenced by the numerous descriptions by spiritual seekers throughout the ages of “the dark night of the soul”.
The progress in terms of development of the intuitive mind follows this same general pattern. Sri Aurobindo observes: “This is indeed its nature that it is a link and transition between present mind and the supermind and, so long as the transition is not complete, there is sometimes a gravitation downward, sometimes a tendency upward, an oscillation, an invasion and attraction from below, an invasion and attraction from above, and at best an uncertain and limited status between the two poles. As the higher intelligence of man is situated between his animal and customary human mind below and his evolving spiritual mind above, so this first spiritual mind is situated between the intellectualised human mentality and the greater supramental knowledge.”
One must also reckon with the long established patterns and habits and limitations at work within each individual being. The spiritual development starts for each individual from the level at which he starts. However well developed the various parts of the being are, they create both obstacles and opportunities for the spiritual growth; but they also represent such strong habitual actions that the old nature will tend to reassert itself at times by resurrecting the habits embedded in the mentality, or the vital and physical tendencies of the specific individual involved.
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 20, The Intuitive Mind, pg. 779