From the Gita's dharma and Cicero's offices to Kant's categorical imperative, Ross's prima facie duties, and Williams' revolt against the 'moral ought'.
What do we owe — and does obligation bind us absolutely, or only as far as our roles, relations, and consequences reach?
Few ideas are as commanding, or as contested, as duty. The Bhagavad Gita tells Arjuna to act from his own dharma without attachment to results; Cicero systematized the 'offices' owed to family, state, and honour; Confucius rooted obligation in the reciprocal bonds of the five relationships. In the modern age Kant made duty the very heart of morality — action from respect for a universal law — and Fichte and Bradley developed the theme of self-realization through one's 'station and its duties'. But the twentieth century pushed back: Ross multiplied duties into plural, conflicting prima facie claims, and Bernard Williams attacked the whole peculiar institution of the 'moral ought' as an alien tyranny over a life. To ask what duty is, is to ask whether anything can bind us unconditionally.
Hindu philosophy
Each person has a duty (svadharma) fixed by their nature and station, and one should perform it without attachment to the fruits of action (nishkama karma). Better one's own duty done imperfectly than another's done well. On the battlefield Krishna teaches Arjuna that acting from duty, offered to the divine and free of egoistic desire, is a path of liberation, not bondage.
Bhagavad Gita, chs. 2–3.
Roman Stoicism / eclecticism
Building on the Stoic Panaetius, Cicero distinguishes duties (officia) that flow from the honourable — wisdom, justice, courage, temperance — and shows how the truly useful never conflicts with the honourable. Duties are graded by our relationships, owed first to country and parents, then to the wider circles of humanity. His On Duties became the West's most influential handbook of practical morality.
On Duties (De Officiis).
Confucianism
Duty (yi, righteousness) is what one ought to do because it is fitting, done for its own sake rather than for gain — 'the noble person understands righteousness, the small person understands profit'. Obligations are concrete and relational, fixed by the five bonds of ruler–subject, parent–child, husband–wife, elder–younger, and friend–friend. To rectify names is to make each person live up to the duties their role names imply.
The Analects.
Roman Stoicism
Duty is doing the work of a human being — acting for the common good as a part serves the whole — and rising each morning to it however unwilling the body. We are made for cooperation, so to shirk one's social task is to war against nature. Perform each act as if it were your last, with justice and without complaint, indifferent to reward.
Meditations.
Natural law
Duties derive from natural law and divide into duties to God, to oneself, and to others, the fundamental one being 'sociality' — to cultivate and preserve peaceable society. Because human beings are needy and mutually dependent, reason discovers obligations binding on all rational beings prior to civil law. His systematic 'duties of man and citizen' shaped Enlightenment moral and legal education.
On the Duty of Man and Citizen (1673).
German idealism / critical philosophy
Only action done from duty — out of respect for the moral law rather than inclination or advantage — has moral worth. The law takes the form of the categorical imperative: act only on a maxim you could will to be a universal law, and treat humanity always as an end and never merely as a means. Duty is unconditional, binding rational agents as such, and its very austerity is the mark of moral freedom.
Groundwork of the Metaphysics of Morals (1785); Critique of Practical Reason.
German idealism
The whole of morality flows from the demand that the self make itself ever more fully self-determining and free. Each person has a determinate duty fixed by their vocation and place among other free beings, whom they must summon to freedom in turn. Conscience is the immediate consciousness of one's concrete duty, and to act on it without hesitation is the moral life.
The System of Ethics (1798); The Vocation of Man.
British idealism
The self is realized not in abstract Kantian universality nor in private pleasure but in 'my station and its duties' — the concrete roles I occupy within a social whole. Morality is being what one is: a member of a family, a community, a state, whose organic life gives content to my obligations. Yet he grants that this ethic of station is not the last word, for the ideal self always outreaches any given social order.
Ethical Studies (1876), 'My Station and Its Duties'.
Ethical intuitionism
There is no single supreme duty but a plurality of 'prima facie' duties — fidelity, reparation, gratitude, justice, beneficence, self-improvement, non-maleficence — each self-evident to a mature mind. When these conflict, no formula decides; we must weigh them by intuitive judgment to find our 'duty proper' in the situation. This pluralism corrects Kant's rigidity and utilitarianism's single measure alike.
The Right and the Good (1930).
Ethical intuitionism
Moral philosophy rests on a mistake if it tries to prove why we ought to do our duty; the demand for such a proof misunderstands obligation. We simply apprehend our particular duties immediately, by a kind of moral perception, just as we grasp self-evident truths in mathematics. To seek a further reason for duty is to convert it into self-interest and lose it.
'Does Moral Philosophy Rest on a Mistake?' (1912).
Utilitarianism
Duty is not a first principle but is derived from utility: an act is a duty when its performance can rightly be exacted and its omission blamed and punished, whether by law, opinion, or conscience. This distinguishes duty (the obligatory) from mere expediency or the meritorious. The sense of obligation is a powerful feeling, but its ultimate sanction and content lie in the promotion of the general happiness.
Utilitarianism (1861), ch. 5.
Analytic ethics (critic of 'morality')
He attacks the 'morality system' with its inflated notion of the 'moral ought' as a special, inescapable, blame-backed obligation that crowds out every other consideration. Real ethical life includes projects, loves, and commitments whose weight is not that of duty, and an obligation can be outweighed by them without moral failure. The system's demand that one always be ready to justify oneself before an impartial tribunal is a distorting and alienating fiction.
Ethics and the Limits of Philosophy (1985).