The truth is that upon which we are now insisting, that reason is in its nature an imperfect light with a large but still restricted mission and that once it applies itself to life and action it becomes subject to what it studies and the servant and counsellor of the forces in whose obscure and ill-understood struggle it intervenes. It can in its nature be used and has always been used to justify any idea, theory of life, system of society or government, ideal of individual or collective action to which the will of man attaches itself for the moment or through the centuries. In philosophy it gives equally good reasons for monism and pluralism or for any halting-place between them, for the belief in Being or for the belief in Becoming, for optimism and pessimism, for activism and quietism. It can justify the most mystic religionism and the most positive atheism, get rid of God or see nothing else. In aesthetics, it supplies the basis equally for classicism and romanticism, for an idealistic, religious or mystic theory of art or for the most earthly realism. It can with equal power base austerely a strict and narrow moralism or prove triumphantly the thesis of the antinomian. It has been the sufficient and convincing prophet of every kind of autocracy or oligarchy and of every species of democracy; it supplies excellent and satisfying reasons for competitive individualism and equally excellent and satisfying reasons for communism or against communism and for State socialism or for one variety of socialism against another. It can place itself with equal effectivity at the service of utilitarianism, economism, hedonism, aestheticism, sensualism, ethicism, idealism or any other essential need or activity of man and build around it a philosophy, a political and social system, a theory of conduct and life. Ask it not to lean to one idea alone, but make an eclectic combination or a synthetic harmony and it will satisfy you; only, there being any number of possible combinations or harmonies, it will equally well justify the one or the other and set up or throw down any one of them according as the spirit in man is attracted to or withdraws from it. For it is really that which decides and the reason is only a brilliant servant and minister of the veiled and secret sovereign.
This truth is hidden from the rationalist because he is supported by two constant articles of faith, first that his own reason is right and the reason of others who differ from him is wrong, and secondly that whatever may be the present deficiencies of the human intellect, the collective human reason will eventually arrive at purity and be able to found human thought and life securely on a clear rational basis entirely satisfying to the intelligence. His first article of faith is no doubt the common expression of our egoism and arrogant fallibility, but it is also something more; it expresses the truth that it is the legitimate function of the reason to justify to man his action and his hope and the faith that is in him and give him that idea and knowledge, however restricted, and that dynamic conviction, however narrow and intolerant, which he needs in order that he may live, act and grow in the highest light available to him. The reason cannot grasp all truth in its embrace because truth it too infinite for it; but still it does grasp the something of it which we immediately need, and its insufficiency does not detract from the value of its work, but is rather the measure of its value. For man is not intended to grasp the whole truth of his being at once, but to move towards it through a succession of experiences and a constant, though not by any means perfectly continuous self-enlargement. The first business of reason then is to justify and enlighten to him his various experiences and to give him faith and conviction in holding on to his self-enlargings. It justifies to him now this, now that, the experiences of the moment, the receding light of the past, the half-seen vision of the future. Its inconstancy, its divisibility against itself, its power of sustaining opposite views are the whole secret of its value. It would not do indeed for it to support too conflicting views in the same individual, except at moments of awakening and transition, but in the collective body of men and in the successions of Time that is its whole business. For so man moves towards the infinity of the Truth by the experience of its variety; so his reason helps him to build, change, destroy what he has built and prepare a new construction, in a word to progress, grow, enlarge himself in his self-knowledge and world-knowledge and their works.
The second article of faith of the believer in reason is also an error and yet contains a truth. The reason cannot arrive at any final truth because it can neither get to the root of things nor embrace the totality of their secrets; it deals with the finite, the separate, the limited aggregate, and has no measure for the all and the infinite. Nor can reason found a perfect life for man or a perfect society. A purely rational human life would be a life baulked and deprived of its most powerful dynamic sources; it would be a substitution of the minister for the sovereign. A purely rational human life would not come into being and, if it could be born, either could not live or would sterilise and petrify human existence. The root powers of human life, its intimate causes are below, irrational, and they are above, suprarational. But this is true that by constant enlargement, purification, openness the reason of man is bound to arrive at an intelligent sense even of that which is hidden from it, a power of passive yet sympathetic reflection of the Light that surpasses it. Its limit is reached, its function is finished when it can say to man, "There is a Soul, a Self, a God in the world and in man who works concealed and all in his self-concealing and gradual self-unfolding. His minister I have been, slowly to unseal your eyes, remove the thick integument of your vision until there is only my own luminous veil between you and him. Remove that and make the soul of man one in fact and nature with the Divine; then you will know yourself, discover the highest and widest law of your being, become the possessors or at least the receivers and instruments of a higher will and knowledge than mine and lay hold at last on the true secret and the whole sense of a human and yet divine living".
—The Human Cycle —The Office and Limitations of the Reason; Sri Aurobindo; pg. 111-114