A key distinction between man and animals is the higher expression of mind and the aspiration towards spiritual realisation, which makes it impossible for man to remain satisfied with the daily round of vital activities and satisfactions which occupy the denizens of the animal kingdom. This is a progressive evolutionary development built on the foundation of the physical and vital life that had developed previously, but not entirely bound by it. There is an increasing force of consciousness at work which expresses itself through higher centres of expression. This is actually the basis of the concept of the chakras and their characteristic force. The lower chakras mirror the physical and vital energies at work and represent the drives toward fulfillment of survival needs and desire for vital satisfactions. As energy flows through the higher chakras, there is a new focus on emotional development and expression, and still higher chakras evidence the working of will and reasoning intelligence. Yet higher chakras, as they begin to open and allow energy to flow, bring about the aspiration for spiritual realisation and the connection with the universal truth of Oneness.
Sri Aurobindo observes: “This upward transference of our will to be and our power of life we have, then, to make the very principle of our perfection. That will, that power must choose between the domination of the vital part in us and the domination of the spirit. Nature can rest in the round of vital being, can produce there a sort of perfection, but that is the perfection of an arrested development satisfied with its own limits. This she can manage in the plant and the animal, because the life and the body are there at once the instrument and the aim; they do not look beyond themselves. She cannot do it in man because here she has shot up beyond her physical and vital basis; she has developed in him the mind which is an outflowering of the life towards the light of the Spirit, and the life and the body are now instrumental and no longer their own aim. Therefore the perfection of man cannot consist in pursuing the unillumined round of the physical life. Neither can it be found in the wider rounds of the mental being; for that also is instrumental and tends towards something else beyond it, something whose power indeed works in it, but whose larger truth is superconscient to its present intelligence, supramental. The perfection of man lies in the unfolding of the ever-perfect Spirit.”
Sri Aurobindo, The Human Cycle: The Psychology of Social Development, Chapter 22, The Necessity of the Spiritual Transformation, pp. 242-243