Duty

The treatment of duty in Sophocles takes its sharpest form in the Antigone, where the heroine is placed between obligations that cannot both be honored. As a subject of the city she is bound by the edict of its ruler, which forbids the burial of Polyneices. As a sister she is bound by the claims of kindred and by the duty, laid on the living by the gods of the household, to bury the dead. As a pious woman she is bound by the demand of the gods below, who require that the body of the fallen be given its proper rites. These obligations do not differ in degree only; they issue from different sources, and each of them is a duty in the full sense. The Antigone is the dramatization of the fact that duties may stand in conflict.

What makes the play exemplary for the tradition is the refusal of either party to deny the reality of the other's claim. Creon does not say that the obligations of kindred are unreal; he insists that the obligations of the citizen must take precedence when the two collide. Antigone does not say that the city's edicts are without force; she insists that the commands of the gods below and of family must take precedence over any edict whose demand is incompatible with them. The tragedy lies in the fact that each is right within the order from which she or he speaks, and that no order larger than both has been put in a position to adjudicate between them. Ismene, by refusing to act at all, represents a third possibility, which is the ordinary prudence of those who see the conflict and step aside.

The problem so formulated belongs to several later discussions. Under Justice it reappears as the conflict of the several justices which claim authority over the citizen; under Law as the conflict of the unwritten and the written; under Family as the collision of the obligations of kindred with those of the political community. What Sophocles adds, and what is properly his contribution to the idea of duty, is the recognition that these conflicts are not necessarily the result of error on one side or the other, and that the agent may be called upon to act in circumstances where no course is available that does not breach some obligation.

The question whether duties can really conflict, or whether a rightly constructed moral theory must rule out such conflicts, is one the later tradition takes up under several heads. Aquinas will argue that where duties appear to conflict, one of them is only an apparent duty, and the appearance of conflict arises from a failure to see this. Kant will attempt a stricter formulation, in which the concept of duty excludes the possibility of a conflict of duties strictly so called. Against these more systematic positions, the Sophoclean scene remains a standing case. Whether tragedy is a way of seeing something that analysis must lose, or whether the analysis corrects what tragedy had made to look inevitable, is a question that the treatments of duty in the later tradition keep returning to.

Plato does not use the word "duty" in the modern sense, but the Republic answers the question that later duty-theorists will inherit: why should a person act justly when injustice might profit him? Thrasymachus insists that justice is the advantage of the stronger, and Glaucon presses the case with the Ring of Gyges, which would make its wearer invisible and free from all social consequences. If justice is only a contract born of mutual weakness, then no one would be just who could get away with injustice. Plato's answer is that justice is not a burden imposed from outside but a condition of the soul's own flourishing. The just person acts rightly because justice is health, and injustice is sickness.

The argument turns on the tripartite soul. Reason, spirit, and appetite each have their proper function, and justice is the arrangement in which each does its own work without usurping another's. Duty, on this account, is not submission to an external command but the natural expression of a well-ordered inner life. The just man does not refrain from theft because a law forbids it; he refrains because his rational part governs and his appetitive part obeys. The analogy with the city reinforces the point: just as the city needs rulers, auxiliaries, and producers each in their proper place, the soul needs its parts harmonized. The man who achieves this harmony will do what is right as naturally as the healthy body performs its functions.

This reasoning has a notable consequence for the concept of obligation. If justice is intrinsic to the soul's good, then the question "why be just?" is like asking "why be healthy?" There is no gap between what one ought to do and what one benefits from doing. Moral obligation is not an imposition but a recognition of what the soul requires for its own completion. Plato never separates duty from self-interest because, properly understood, they coincide.

Aristotle would narrow Plato's account by restricting duty to the virtue of justice alone rather than to virtue in general. The Stoics would extend what Plato implies, connecting duty to a law of reason binding on all rational beings as members of a single cosmic community. Kant would insist that duty be separated from any consideration of self-interest, including the soul's own flourishing. In each case, the discussion takes its departure from the question Plato raises: what makes certain acts binding on rational beings, and what is the ultimate ground of that binding force?

Aristotle narrows Plato's broad identification of justice with the whole of virtue. He agrees that the just person is virtuous, but he distinguishes justice as a particular virtue from justice as the whole of virtue "in relation to another." Courage, temperance, and wisdom perfect the agent; justice alone is directed essentially toward other people. This distinction creates the space for something like a concept of duty, because it identifies a class of actions that are owed rather than merely admirable. The courageous man acts well, but he does not owe his courage to anyone. The just man, by contrast, renders what is due.

Book V of the Nicomachean Ethics provides the framework. Aristotle divides particular justice into distributive and corrective forms. Distributive justice allocates goods according to merit; corrective justice restores equality when one party has taken more than his share. In both cases, the just act is determined by a proportion, not by the agent's feelings or inclinations. The person who distributes offices or punishments must attend to the relevant differences among the recipients and assign shares accordingly. This arithmetic quality gives justice a precision that the other virtues lack. Courage admits of many styles; justice admits of calculation.

Aristotle also extends duty through his account of friendship. In Books VIII and IX, he argues that friends owe each other specific goods depending on the kind of friendship they share. Friends of virtue owe each other honesty and mutual improvement; friends of utility owe fair exchange. These are genuine obligations, not optional generosities. The failure to fulfill them is not merely a shortcoming but an injustice. By connecting friendship to obligation, Aristotle shows that duty extends beyond the public sphere of law and distribution into the private sphere of personal relationships.

Aristotle bequeaths to later thinkers a concept of duty rooted in what one person owes another, measured by rational proportion. The tension he leaves open is between the public and private faces of obligation: justice is owed to fellow citizens by law and calculation, but friendship generates its own duties of honesty and loyalty that no law specifies. Hobbes will collapse this distinction by making all genuine obligation dependent on sovereign enforcement; Kant will try to restore it by grounding both in the same rational law.

Cicero's On Duties is the first sustained treatise on duty as such in the tradition of the Great Books, and it fixes for the tradition a set of distinctions it will not afterward be able to do without. The work is organized around two subjects: what is honorable (honestum) and what is useful (utile), together with the question of what is to be done when the two appear to conflict. The four cardinal virtues of wisdom, justice, fortitude, and temperance are each considered under the first head, and the various forms of practical advantage under the second. The work is addressed to Cicero's son at the end of his own life, and its tone is that of a Roman statesman setting out for the young the rules by which the life of a gentleman and a citizen is to be conducted.

The substance of the treatise is largely Stoic in its provenance, drawn from Panaetius, though Cicero makes free to correct the Greek philosopher where Roman experience seems to him to require it. The four-fold division of the honorable is Stoic; the treatment of the special duties that arise from particular offices, stations, or times is also Stoic, though Cicero develops it in directions of his own. His characteristic move is to insist that the apparent conflict between the honorable and the useful is in every case only apparent. What is useful but dishonorable is not, in the long view, useful at all. The man who deserts his post for the sake of his safety, or who betrays a friend for the sake of gain, will find in the end that the loss to his character is greater than any advantage he has secured. The third book of On Duties is devoted to the cases in which this must be argued through in detail.

The questions Cicero raises belong also to the treatments of Virtue and Vice, of Justice, of Honor, and of Custom and Convention. Under the idea of Duty, what he contributes is the conception of an organized account of the rules of conduct appropriate to the several stations of life, together with the claim that these rules, properly understood, never require the sacrifice of character to advantage. Whether this is a claim the facts of moral life will support is a question the later tradition takes up repeatedly.

Aquinas will incorporate much of the Ciceronian treatment into his own account of the cardinal virtues and of the natural law. Kant, whose analysis of duty belongs to a quite different philosophical tradition, nevertheless took On Duties as the most distinguished pre-modern treatment of its subject and refers to it with respect. The question whether duty admits of conflict, and whether a rightly ordered life can always reconcile the honorable and the useful, remains one of the standing questions of the field, and Cicero's answer is the one against which the later alternatives are measured.

Epictetus approaches the concept of duty through the fundamental distinction between what lies within our power and what does not. The Aristotelian had asked what justice demands in a given situation; Epictetus asks what your role demands. Every person occupies a set of stations: son, citizen, friend, human being. Each station carries specific obligations, and fulfilling those obligations is what the Stoics call kathekon, or "appropriate action." Epictetus, who had been a slave before his freedom and his career as a teacher, knew from direct experience that the performance of duty does not depend on outward circumstance. A person can fulfill his obligations in chains or in a palace; what matters is the quality of his rational assent.

The key distinction is between the prohairesis (the faculty of choice) and everything external. Health, reputation, freedom, even life itself lie outside the sphere of moral duty. What lies inside is the ruling principle of reason, the hegemonikon, which must be kept clean and consistent. Duty, for Epictetus, is not primarily about producing good outcomes or rendering what is owed to others. It is about maintaining the integrity of one's rational faculty in every circumstance. The father who grieves excessively for a dead child has failed in his duty, not because grief is forbidden, but because he has surrendered his prohairesis to something outside his control.

This produces a distinctive account of social obligation. Epictetus does not deny that we owe things to other people; he insists that we owe them the proper performance of our roles. The brother who wrongs you is still your brother, and your duty is to act as a brother should, regardless of his behavior. You cannot control his actions, only your own. This detachment from outcomes gives Stoic duty an unconditional quality that will later resonate in Kant's categorical imperative. The Stoic does right not because it will produce good results, but because reason requires it.

Marcus Aurelius would apply this framework to the conditions of political rule, examining whether the principles that govern the conduct of a private person can also govern the conduct of an emperor. Kant would set aside the Stoic metaphysical cosmology while preserving what he regarded as its central insight: that duty is unconditional, rational, and independent of consequences.

The Meditations are private notes in which Marcus Aurelius addresses himself, as emperor, on the practice of duty under the conditions of political life. His concern is less to define duty than to sustain it. Where Epictetus set out the theoretical framework of Stoic ethics, Marcus records the effort required to apply it when the circumstances of rule press in the contrary direction. Each entry returns to the same precepts: hold fast to rational nature, attend to the common good, fulfill the obligations of the station one occupies.

The answer is always the same: return to your rational nature. Marcus reminds himself repeatedly that he is a part of a larger whole, that the rational soul participates in the logos that governs the cosmos. Duty is not an arbitrary imposition but the natural function of a rational being embedded in a community. The bee does not ask whether making honey serves its interests; it acts according to its nature. The emperor must do the same. Each morning he tells himself that he will encounter ungrateful, arrogant, and deceitful people, but that none of this releases him from his obligation to work for the common good. His station demands it, and his nature as a rational being demands it.

What Marcus adds to Epictetus is the raw honesty about how difficult duty is. He does not pretend that Stoic practice eliminates suffering or reluctance. He records his weariness, his temptation to withdraw, his disgust with court life. But he also records his resolution to continue. Duty, for Marcus, is not a single heroic act but a daily discipline of returning to one's post. The soldier who deserts once has failed; the soldier who returns to his position every morning, despite exhaustion, fulfills his duty through persistence rather than through the absence of resistance.

The Meditations show what the Stoic conception of duty looks like when practiced under the pressures of political life over an extended period. Kant would later maintain that duty must be performed from duty alone, without regard for inclination or desire. The Meditations may be read as an account of what this requirement means in practice and what it demands of the person who attempts to fulfill it.

Aquinas inherits Aristotle's identification of duty with justice but embeds it in a much larger framework. For Aristotle, obligation arises from the structure of human relationships; for Aquinas, it arises from the participation of rational creatures in the eternal law of God. Natural law is this participation: the set of precepts that human reason can discern by reflecting on the inclinations built into human nature. The first precept of natural law is that good is to be done and pursued, and evil avoided. From this, specific duties follow: to preserve life, to live in society, to seek truth, to worship God.

The crucial move is the claim that natural law makes all virtues, not just justice, matters of obligation. Aristotle had reserved the language of duty for justice because justice alone concerns another's good. Aquinas agrees that justice has a special connection to obligation, since justice literally renders what is owed. But he argues that natural law also commands temperance, courage, and prudence, because these virtues are necessary for human beings to fulfill their proper end. The intemperate man does not merely harm himself; he violates the order that reason prescribes. Duty, for Aquinas, extends as far as the rational ordering of human life.

This framework gives Aquinas a powerful tool for evaluating positive law. Human law derives its binding force from natural law. A statute that contradicts natural law is not merely unjust; it is not truly law at all, and the subject has no duty to obey it. This is not a license for anarchy, since Aquinas also insists that the common good generally requires obedience even to imperfect laws. But it establishes a principled limit on political obligation. The duty to obey the state is real but conditional: it depends on the state's conformity to a higher law that neither the state nor any human authority creates.

Aquinas gives the tradition a theory of duty that is simultaneously rational and theological. Locke will draw on the natural law framework while loosening its connection to revealed theology. Kant will attempt to preserve the unconditional character of moral obligation while stripping away both God and nature as its ground.

Hobbes departs sharply from the ancient and medieval accounts of duty. There is no natural law in Aquinas's sense, no rational order built into the cosmos that human beings can read off and obey. There is no natural justice in Aristotle's sense, no inherent proportion that determines what one person owes another. In the state of nature, every person has a right to everything, including the bodies of others. Where everyone has a right to everything, no one has a duty to anything. Obligation begins only when individuals covenant together to create a sovereign power capable of enforcing agreements. Without the sword, covenants are mere words.

The logic is mechanical. Human beings are driven by desire and aversion, and their fundamental desire is self-preservation. Reason discovers that the best means to self-preservation is peace, and peace requires that each person surrender his natural right to all things, transferring it to a sovereign. The laws of nature that Hobbes identifies (keep your covenants, be grateful, be accommodating) are theorems of reason about the conditions of peace, not divine commands or intuitions of justice. They become obligatory only when there is power sufficient to compel obedience. The obligation is entirely conditional on the sovereign's ability to protect; when protection fails, the duty of obedience ceases.

Whereas for Plato, Aristotle, the Stoics, and Aquinas, duty existed prior to and independent of political authority, for Hobbes political authority is itself the source of duty. Justice and injustice have no meaning outside the Commonwealth. The man in the state of nature who kills his neighbor commits no injustice, because injustice is the violation of covenant, and without a sovereign there is no covenant to violate.

Locke will attempt to rescue natural law from Hobbes's demolition while accepting the contractarian framework. Kant will reject Hobbes's reduction of morality to prudence but will share his conviction that the ground of duty must be found in reason rather than in nature or divine command.

Locke occupies the middle ground between Hobbes and the natural law tradition, and his account of duty reflects this mediating position. In the Essay Concerning Human Understanding, he identifies three laws by which human actions are judged: the divine law, the civil law, and the law of opinion or reputation. Each creates a distinct form of obligation. God's law determines what is sin and what is duty in the strictest sense. Civil law determines what is criminal and what is innocent. The law of opinion determines what is virtuous and what is vicious in the eyes of one's community. These three do not always agree, and Locke is honest about the tension between them.

The divine law provides the ultimate ground of moral obligation. Locke argues that God, as the creator and preserver of human beings, has the authority to command them, and that reason can discover the content of his commands. This preserves the natural law tradition against Hobbes's reduction of all obligation to sovereign command. But Locke also acknowledges, more candidly than Aquinas, that human beings are often motivated less by divine law than by the rewards and punishments attached to civil law and social reputation. People avoid theft not primarily because God forbids it, but because the state punishes it and their neighbors despise it. The moral philosopher may regret this, but the political thinker must work with it.

In the Second Treatise, Locke applies this framework to political obligation. The state of nature is not Hobbes's war of all against all; it is a condition governed by natural law, in which human beings have real duties to one another, including the duty not to harm another's life, liberty, or property. Political society arises not from the desperate need to escape anarchy but from the inconvenience of each person being judge in his own case. The social contract creates civil duties, but these are limited by the natural rights and natural duties that precede the contract. Government that violates natural law forfeits its claim to obedience.

The two strands in Locke's account were taken in different directions by later thinkers. Kant will take the emphasis on rational law and purify it into the categorical imperative, stripping away both divine command and social opinion. Mill will take the emphasis on consequences (pleasure and pain) and build it into a systematic utilitarianism.

Kant holds that all moral obligations derive from a single principle, one that is a law of reason itself and requires no appeal to God, nature, happiness, or social convention. He claims to have found, and to have shown that this principle is a law of reason itself, requiring no appeal to God, nature, happiness, or social convention. The categorical imperative commands unconditionally: act only according to that maxim which you can at the same time will to be a universal law. An action has moral worth only when it is performed from duty, that is, from respect for the moral law, and not from inclination, self-interest, or sympathy. The shopkeeper who gives honest change because honesty is good for business acts in accordance with duty but not from duty; his action has no moral worth.

The separation of duty from inclination has generated some of the most persistent objections to Kant's moral philosophy. Against the entire ancient tradition, he denies that virtue and happiness naturally coincide. A person might do the right thing and suffer for it; a person might be constitutionally kind and receive no moral credit for it. Only the will that acts from duty, that recognizes the moral law as binding and obeys it for that reason alone, deserves moral praise. This produces the famous test cases. The man who has lost all desire to live but preserves his life out of duty acts morally; the man who enjoys helping others and does so gladly does not act from duty and therefore does not act morally in the strict sense. Kant does not condemn kindness, but he insists that it has no specifically moral value.

The categorical imperative generates specific duties through its various formulations. The universalizability test rules out lying, promise-breaking, and selfishness, because the maxims behind these actions cannot be universalized without contradiction. The humanity formula ("treat humanity, whether in your own person or in that of another, always as an end and never merely as a means") generates duties of respect, including duties to oneself. Kant distinguishes perfect duties (which admit of no exception, such as the duty not to lie) from imperfect duties (which allow latitude in how they are fulfilled, such as the duty to develop one's talents). The entire system is derived from reason alone, without any empirical premises about human nature or divine commands.

Hegel would argue that the categorical imperative is an empty form requiring the concrete content supplied by the institutions of ethical life. Mill would reject the a priori method, insisting that duty derives its content from the consequences that actions produce for human happiness. These objections raise the question of whether the formal character of the moral law can by itself determine the particular duties it is supposed to generate.

Hegel accepts Kant's insight that duty is rational and universal, but he rejects the formalism that strips duty of all concrete content. The categorical imperative, Hegel argues, is an empty procedure that can rationalize anything or nothing. "Act so that your maxim could become a universal law" tells you nothing about what to do unless you already inhabit a specific ethical world with specific institutions, roles, and expectations. Kant's morality (Moralitat) is abstract and subjective; what is needed is ethical life (Sittlichkeit), in which duty is embedded in the actual institutions that rational freedom has created.

The Philosophy of Right traces the development of duty through three spheres. In the family, duty takes the form of love and mutual care; members do not relate to each other through contracts or calculated obligations but through an immediate ethical unity. In civil society, duty appears as the obligation to work, to honor contracts, and to contribute to the system of needs that sustains economic life. In the state, duty reaches its highest form: the citizen's obligation to the political community that makes freedom actual. Each sphere has its own logic, and the duties appropriate to one sphere cannot simply be transferred to another. The father's duty to his children is not contractual; the merchant's duty to his creditors is not sentimental.

Hegel's deepest objection to Kant is that abstract duty, duty considered apart from the social world in which it is practiced, is a tyranny of the ought. The Kantian moral subject stands perpetually over against a world that fails to match the moral law, and duty becomes an infinite demand that can never be satisfied. Hegel wants to show that the rational is actual: that duty is not a standard imposed on the world from outside but the inner logic of existing social institutions, properly understood. The person who fulfills his station's duties with insight and conviction does not experience duty as a constraint but as the expression of his own rational freedom.

Mill would challenge Hegel from the utilitarian direction, arguing that duty must be grounded in the consequences that actions produce for human happiness rather than in the rational structure of institutions. Marx would apply the dialectical method against Hegel's own conclusions, arguing that existing institutions are not the realization of freedom but its concealment, and that the question of duty cannot be separated from the question of which social arrangements make genuine human development possible.

Mill brings the conversation on duty back to consequences. Against Kant, he argues that no formal principle of reason can generate substantive moral obligations. Against Hobbes, he insists that duty is real and binding, not merely a product of sovereign command. The ground of duty is the principle of utility: actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse. Duty is not obedience to a categorical imperative but the obligation to produce the greatest good for the greatest number.

Chapter V of Utilitarianism provides Mill's most careful analysis. He distinguishes duty from mere expediency. Not every useful action is a duty; duty applies specifically to those actions whose omission deserves punishment, whether legal, social, or internal (the pang of conscience). Justice, the strongest form of duty, concerns those moral rules that protect the most vital human interests. The duty not to harm, the duty to keep promises, the duty to treat people impartially: these are not arbitrary rules but the indispensable conditions of social cooperation. They carry the strongest obligatory force because the interests they protect are the most important.

Mill also addresses the scope of duty in On Liberty. The individual has no duty to society regarding actions that affect only himself; society may advise or persuade, but it may not compel. Duty to others begins only where one's actions harm or threaten to harm their interests. This harm principle limits the reach of moral obligation more sharply than any previous thinker had done. Kant's duty extends to self-regarding actions (you must develop your talents, you must not commit suicide); Mill denies that society has any claim on such choices. The result is a concept of duty that is simultaneously consequentialist in its foundation and liberal in its scope.

The question Mill raises against Kant has continued to organize discussion of moral obligation. Whether duty is grounded in the rational form of the moral law, as Kant maintains, or in the consequences that actions produce for human happiness, as Mill argues, has remained a dividing question in moral philosophy, each position generating objections that the other must answer.