The limitations of the Reason mean that once it engages itself to the service of any force or direction, it finds ways to marshall the powers of logic and argument to justify whatever it is being asked to justify. When the desire-will of the vital nature chooses a path, the reason comes forward to prove the rightness of that direction. When any particular ideal, religious notion, or philosophy engages the reason, once again, it is able to justify that path. The reason is no ultimate arbiter of truth and right, but is realistically nothing more than a powerful minister or servant.
Sri Aurobindo observes: “…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 earthy 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 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. … 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 this veiled and secret sovereign.”
Sri Aurobindo, The Human Cycle: The Psychology of Social Development, Chapter 12, The Office and Limitations of the Reason, pp. 120-121