Sri Aurobindo observes: …”purification, liberation, perfection, delight of being are four constituent elements of the Yoga,–suddhi, mukti, siddhi, bhukti.” These represent stages in the yogic process to address and overcome the confused working of the lower nature, help the seeker rise above the limitations imposed by that nature, and systematically transform and uplift the nature and the action that flows from it. The human individual can progress using the instruments of body, life and mind, to a certain degree, after which the inherent limits of these instruments become the stumbling block. The uncertain, mixed and confused action of the nature needs to be addressed for ultimate perfection to be achieved. “That mixed and confused action has to be mended; purification is an essential means towards self-perfection. All these impurities and inadequacies result in various kinds of limitation and bondage; but there are two or three primary knots of the bondage,–ego is the principal knot,–from which the others derive. These bonds must be got rid of; purification is not complete till it brings about liberation.”
For those whose intention is to escape the outer life, this step of liberation may be sufficient; but for the practitioner of the integral Yoga there is still the need to bring about the perfection of the instruments and the action in the world. …”after a certain purification and liberation has been effected, there is still the conversion of the purified instruments to the law of a higher object and utility, a large, real and perfect order of action. By the conversion man can arrive at a certain perfection of fullness of being, calm, power and knowledge, even a greater vital action and more perfect physical existence. One result of this perfection is a large and perfected delight of being, Ananda.”
Ananda comes about through shifting the standpoint away from the human to the divine standpoint, where the ultimate principles of Sat-Chit-Ananda, Existence, Consciousness-Force and Bliss, are manifest. Thus, through practice of these four constituent elements, the seeker systematically loosens the bondage of the lower nature and transitions to the higher nature and the divine standpoint as the basis for his existence, awareness, action and delight of being.
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 4, The Perfection of the Mental Being, pg. 613