The action of the intelligent Reason and Will is hampered by the distortions caused by the desire-soul of the lower nature. The reasoning process is biased and tainted by the vital impulse and the action is distorted by the habitual pattern of behavior that constitutes the nature of the vital.
Sri Aurobindo observes: “The intelligence coloured by desire is an impure intelligence and it distorts Truth; the will coloured by desire is an impure will and it puts a stamp of distortion, pain and imperfection upon the soul’s activity.” and further: “All subjection of the Buddhi to the sensations and impulses is an impurity.”
The yogic process of detachment from involvement in the action of the outer Nature aids the seeker in overcoming the impulse of desire from its distorting influence. “The thought and will have to stand back detached from desire, troubling emotion, distracting or mastering impulse and to act in their own right until they can discover a greater guide, a Will, Tapas or divine Shakti which will take the place of desire and mental will and impulse, an Ananda or pure delight of the spirit and an illumined spiritual knowledge which will express themselves in the action of that Shakti. This complete detachment, impossible without an entire self-government, equality, calm sama, samata, santi, is the surest step towards the purification of the Buddhi. A calm, equal and detached mind can alone reflect the peace or base the action of the the liberated spirit.”
People generally associate detachment with abandonment of the life in the world, and hold that action in society and in worldly activity is not possible without the force of desire. Sri Aurobindo points us toward a fully active life that founds itself on the divine standpoint of an instrument of the spirit carrying out the divine intention in the manifestation, without personal desire or attachment mixing in or confusing the pure and powerful action of the Divine in Nature.
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 7, Purification–Intelligence and Will, pg. 642