We must remember that duty is an idea which in practice rests upon social conceptions. We may extend the term beyond its proper connotation and talk of our duty to ourselves or we may, if we like, say in a transcendent sense that it was Buddha's duty to abandon all, or even that it is the ascetic's duty to sit motionless in a cave! But this is obviously to play with words.
Duty is a relative term and depends upon our relation to others. It is a father's duty, as a father, to nurture and educate his children; a lawyer's to do his best for his client even if he knows him to be guilty and his defence to be a lie; a soldier's to fight and shoot to order even if he kill his own kin and countrymen; a judge's to send the guilty to prison and hang the murderer. And so long as these positions are accepted, the duty remains clear, a practical matter of course even when it is not a point of honour or affection, and overrides the absolute religious or moral law. But what if the inner view is changed, if the lawyer is awakened to the absolute sinfulness of falsehood, the judge becomes convinced that capital punishment is a crime against humanity, the man called upon to the battlefield feels, like the conscientious objector of today or as a Tolstoy would feel, that in no circumstances is it permissible to take human life any more than to eat human flesh? It is obvious that here the moral law which is above all relative duties must prevail; and that law depends on no social relation or conception of duty but on the awakened inner perception of man, the moral being.
There are in the world, in fact, two different laws of conduct each valid on its own plane, the rule principally dependent on external status and the rule independent of status and entirely dependent on the thought and conscience. The Gita does not teach us to subordinate the higher plane to the lower, it does not ask the awakened moral consciousness to slay itself on the altar of duty as a sacrifice and victim to the law of the social status. It calls us higher and not lower; from the conflict of the two planes it bids us ascend to a supreme poise above the mainly practical, above the purely ethical, to the Brahmic consciousness. It replaces the conception of social duty by a divine obligation. The subjection to external law gives place to a certain principle of inner self-determination of action proceeding by the soul's freedom from the tangled law of works. And this, as we shall see,—the Brahmic consciousness, the soul's freedom from works and the determination of works in the nature by the Lord within and above us,—is the kernel of the Gita's teaching with regard to action.
.... Sri Aurobindo