Duty

To have a duty is, above all, to be subject to a binding, normative requirement. This means that unless there are exculpating reasons someone who has a duty is required to satisfy it, and can be justifiably criticized for not doing so. Having a duty to do something is like having been given a command by someone who has a right to be obeyed: it must be done.

Sometimes we speak as if we have duties to individuals (such as persons and institutions). So, for example, if Jones makes a promise to Smith, then Jones has a duty to Smith to keep the promise. We also talk as if we have duties to perform, or to refrain from performing, types of actions, for instance, a duty to help those in need. Even if the performance of such a duty involves treating an individual in a certain way, the duty may not be to that individual. For example, a duty to be charitable might not be a duty to anyone, not even the recipient of the charity.

An important feature of duties is that they provide some justifying reason for action. If we explain why we did something by saying that it was our duty, we are offering a justification for the action. Such a justifying reason does not depend on the entire nature of the action. For example, if we make a promise, we have some justifying reason for keeping it, regardless of what was promised, or to whom the promise was made. Again it is like a command. If we are given a command by someone with a right to be obeyed, we have some justification for obeying it, no matter what we are commanded to do. On some views, however, the justifying reason we have for doing something because it is required by duty may not be decisive: we may have an even better reason for doing something else. None the less, that something is required by duty provides some justifying reason for doing it.

Talk about duties is found in many areas; we speak, for example, of legal duties, moral duties, professional duties, the duties of a scholar and, even, matrimonial duties. This discussion will focus on moral duty, but may have wider application.