Duties come in a wide variety of types. Everyone is pretty familiar with the distinction between legal and moral duties, and between negative duties that constrain our actions, and positive duties that require us to act in a certain way. But these are very broad-brush distinctions. As always, the real world of everyday morality and law is more complex. In fact, differences between duties can be drawn on a host of distinct dimensions. Sometimes it is appropriate to skate over these subtleties in making an argument or propounding a position. Sometimes it is appropriate to conflate the categories, and presume that all imperfect duties are not stringent, say, or that they can’t be made legal. For the other cases, though, taking some time to make the appropriate distinctions can be fruitful. With this in mind, here is an attempt at a comprehensive taxonomy of duties, distinguished over seven dimensions (meaning that an exhaustive description of a duty would require plotting its location in seven-dimensional space!).
Where there is an orthodox term for the type of duty I have used it; where there is not, I have selected one, or coined one. For the most part orthodoxy does not prevail in this arena, so be aware that many of the terms below (especially ‘imperfect duty’) are regularly invoked in opposition to the meanings I stipulate below.
One. The Legality-Morality Dimension: Some duties are legal – to fail to perform the duty is held to be a breach of law, and to make one the object of legal sanction or punishment. Other duties are only moral; one should definitely do them, as a matter of proper moral conduct. However, one is not subject to legal sanction if one fails to comply with them. One further and special form of moral duties is supererogatory duties. These duties are not required – they are moral ideals to aim for, but one does not fail morally by not performing them.
As always, the situation is a little more complicated; for instance there are quasi-legal duties: duties where the legal status is not entirely clear. These commonly arise in the context of international law under the rubric ‘soft law’. In that context it is, for example, quite possible to have a duty that is accepted as legally required, but for there to be no court that can or must adjudicate on it, and no legal mechanism for sanctioning states or individuals that fail such duties.
Two. The Stringency Dimension: This dimension tracks the ethico-political importance of the duty. A stringent duty is one that implies a high degree of wrongdoing if one fails it. For example, it is widely held that failing to respect a right (actively assaulting someone, for example) is worse than failing to help them (say as a Good Samaritan). The Stringency Dimension is linked to the legality-morality dimension, but it is distinct from it. For instance, betraying a friendship or having a marital affair are widely thought much more morally serious than getting a fine for speeding or littering, those these latter are legal duties. Equally, there is an obvious different in stringency between some crimes (assault) and others (jaywalking).
Three: The Agent Dimension: This dimension tells us who the duty-holder is. A universal duty applies to everyone all the time. A circumstantial duty applies to anyone who finds themselves in a particular situation (such as an emergency when a young child falls into a pool).
A special duty, on the other hand, applies only to one person or one class of people. Often (though not always) a special duty is held because of some historical relationship between two people. For instance, the special duty from Amy to Bob can have arisen out of Amy’s consent or contract, or the role she has assumed (as Bob’s adopted parent, say), or because of her prior violation of Bob’s rights, or perhaps simply because she and Bob are from the same community or otherwise have a shared identity.
Four: The Subject Dimension: This dimension delineates who the duty-recipient or beneficiary is. A general duty is one owed (all other things equal) to everyone, such as the duty not to murder. In contradistinction, a specified duty is one owed to just some specific person or class of people. A specified duty might be created along the same methods as the special duty above: Amy’s promise to Bob creates a special, specified duty from Amy to Bob. But other cases are possible. An important set of specified duties are the ones owed by state authorities to all their citizens, or more broadly to all those in their territory or under their control. A state’s bill of rights, or constitutional guarantees, or commitments under international human rights law are (for the most part) specified in just this way.
Institutions apart from the state will often take on board specified duties in order to keep their operations tractable and focused – for instance the UNHCR has specified duties to refugees and internally displaced persons, while UNICEF has specified duties to children. More generally, it is often held that we all have distinct specified duties to children, because of their vulnerable nature.
Five: The Discretion Dimension: Duties can differ in the types of discretion they allow the duty-holder. Duties that have very little discretion are perfect duties. But for many duties, duty-holders have substantial discretion over how, when, where and to whom they fulfil their duties. When there is a significant level of discretion, these duties are termed imperfect duties. (Note that this dimension is quite separate from the legality-dimension; in particular, imperfect duties are not (necessarily) supererogatory.) Discretion can appear in some respects but not in others. For example, if there is a parental duty to work towards the happiness of their children’s lives (a duty my children, at least, propound) then there is wide discretion in how this is performed; I might take them to the movies tomorrow, or play with them down at the creek this afternoon. It is up to me. But there is no discretion regarding the agent or subject of this duty– it is I who owe the duty to my children. When there is a fairly determinate goal set down, and the duty-holder and duty-recipient are determined, then this type of imperfect duty might be called a responsibility. So the imperfect duty of parents to bring up their children well is a responsibility.
Imperfect duties themselves can be understood in a variety of ways: consider the different ways we might have an imperfect duty of charity. First, we might have an imperfect duty to develop certain sorts of emotional dispositions, for example; to develop the traits of character known as virtues. In this case we are required to work towards having a charitable emotional character. Second, we might be required to achieve a quite determinate goal – such as the alleviation of the situation of the homeless people in our neighbourhood – but be allowed to do so in a wide variety of ways. Third, the imperfect duty might require us to take on board, as one part of our larger life-plan, an open-ended goal of alleviating poverty. Here we are required to become serious about helping needy others in the same way we might say a person is serious about a relationship or serious about a vocation. Fourthly and finally, we might have to perform a certain number or threshold of charitable acts – such as duties of almsgiving or paying tithes. All these are imperfect duties of charity, in that they all aim to better the situation of the needy, and give the duty-holder discretion over precisely how this is done. But they are each somewhat distinct from one another, and an actor following one duty rather than another would respond differently to different situations.
One further word on imperfect duties is worth noting (at least, I hope it is worth noting, as I am currently working on the topic). ‘Discretion’ is an ambiguous word. Often it connotes judgment. In such cases there may be criteria for what the result of the judgment should be. Observers looking in from the outside may not be able to tell if those criteria were judiciously acted upon, but there may nevertheless be an objective answer as to what the result of the judgment should have been in a particular case. In these cases, even though you have discretion, you can get it wrong. Other times ‘discretion’ can mean subjective choice. Here there is no judgment and no criteria – you can literally choose whatever you want, and cannot possibly be wrong. Any time ‘discretion’ is used in the context of a moral duty, it is often worth thinking for a moment about whether judgment or subjective choice (or a subtle mix of the two) is being implied.
Note however, that discretion about how to perform an imperfect duty is not discretion about whether to perform an imperfect duty per se. An imperfect duty is still a duty, and should not be assumed to be supererogatory (an all-too-familiar error in both theory and practice).
Six: The Directedness Dimension: Some duties are owed to specific others, and others are not. A duty that Amy owes to Bob, arising from her promise, is a directed duty. It is not merely that Amy should do what she promised, it is that Amy owes it to Bob in particular that she do it. If she doesn’t do it, then it is Bob that is wronged, and in such situations it will usually be Bob that is owed compensation or apology. Other duties are non-directed because the duty-recipients are unclear or diffuse. Amy shouldn’t pollute the air with her smokestacks, but she doesn’t owe that duty to Bob, even if he is a suffering asthmatic. (Coming at the issue of duties from the perspective of rights, we might also speak of non-directed rights, where it is clear that street-urchin Amy is not having her right to education provided, but it is unclear who exactly is failing in their duty to Amy. There is a rights-claim, but it does not match up neatly with any vested duty in any particular person.)
Note that directedness is related to, but not quite the same as, the special-specified properties noted above on dimensions three and four. Amy might have a duty to better Bob’s situation (so the duty is special to Amy and specified to Bob), but she might not owe that duty to Bob – she may owe the duty to Connie. This might happen, for example, if Amy promised Connie she would help Connie’s father Bob around his house while Connie was away on holidays.
Seven: The Mode Dimension: This dimension determines the basic type of action that the duty-holder must perform. It may also be called the ‘directness’ of the duty, as it describes how close the duty is to the effect it is designed to achieve, or the threat it is hoping to assuage.
The most basic distinction on the mode dimension is of course the distinction between negative and positive duties. A negative duty is an ‘action constraint’ – it precludes a person from acting in a particular, determined way. Very often, negative duties foreclose acting in ways that harm others, and for this reason are often stringent and legal. A positive duty, on the other hand, propels a duty-holder into action, requiring her to perform some action or to pursue some goal.
Positive and negative duties come in a variety of modes. Approaching duties from the perspective of rights, theorists and lawyers have distinguished duties of (i) respecting rights: negative duties not to violate rights; (ii) protecting rights: positive duties to protect against rights-violations by third parties; (iii) promoting rights: positive duties to undertake specific actions to structurally contribute to a rights-respecting environment; (iv) facilitating rights: negative duties to alter one’s other actions to structurally contribute to a rights-respecting environment; and finally duties of (v) providing rights: positive duties to give people the necessities of life (these may also be called remedial or restorative duties, since when people do not have these necessities it is usually of a prior rights violation).
Any given duty may thus be mapped onto the seven-dimensional space. So we may say, to give a (contentious) account of the duty to rescue a drowning child by way of example, that this duty is a moral, stringent, circumstantial, specified, perfect, directed and rights-providing duty.
Of course, there are linkages between each of the dimensions. If a duty is imperfect, then that will make it harder (though not impossible – think of holding a ‘duty of care’ or a legal responsibility) to impose legal sanctions for its failure. The linkages, however, are only rarely conceptual in nature. We should be careful about swift assumptions that presence in one category of one dimension determines the duty’s properties on another dimension.