Existence manifests in an ascending series of powers, starting with the physical level, then expressing the vital, life level. Then we see the mind evolve and following that the spiritual energy. Each level has its own powers of understanding, principle of action and limitations, up to the spiritual level, which, as the level at which Oneness is perceived, is able to understand the more complete truth of the interconnected nature of all existence. Thus, the principle of the life-energy is to act as if the being is independent and separated from the rest of creation, to establish it with its own existence, while ideas that arise at the mental level, lacking the complete vision and insight of oneness, are necessarily incomplete and restricted.
Sri Aurobindo observes: “Life differs from the mechanical order of the physical universe with which the reason has been able to deal victoriously just because it is mechanical and runs immutably in the groove of fixed cosmic habits. Life, on the contrary, is a mobile, progressive and evolving force, — a force that is the increasing expression of an infinite soul in creatures and, as it progresses, becomes more and more aware of its own subtle variations, needs, diversities. The progress of Life involves the development and interlocking of an immense number of things that are in conflict with each other and seem often to be absolute oppositions and contraries. To find amid these oppositions some principle or standing-ground of unity, some workable lever of reconciliation which will make possible a larger and better development on a basis of harmony and not of conflict and struggle, must be increasingly the common aim of humanity in its active life-evolution, if it at all means to rise out of life’s more confused, painful and obscure movement, out of the compromises made by Nature with the ignorance of the Life-mind and the nescience of Matter. This can only be truly and satisfactorily done when the soul discovers itself in its highest and completest spiritual reality and effects a progressive upward transformation of its life-values into those of the spirit; for there they will all find their spiritual truth and in that truth their standing-ground of mutual recognition and reconciliation. The spiritual is the one truth of which all others are the veiled aspects, the brilliant disguises or the dark disfigurements, and in which they can find their own right form and true relation to each other. This is a work the reason cannot do. The business of the reason is intermediate: it is to observe and understand this life by the intelligence and discover for it the direction in which it is going and the laws of its self-development on the way. In order that it may do its office, it is obliged to adopt temporarily fixed view-points none of which is more than partially true and to create systems none of which can really stand as the final expression of the integral truth of things. The integral truth of things is truth not of the reason but of the spirit.”
Sri Aurobindo, The Human Cycle: The Psychology of Social Development, Chapter 20, The End of the Curve of Reason, pp. 213-214