What is the difference between perfect and imperfect duties?

Perfect duties, such as the duty not to make false promises, are strict requirements owed to assignable persons that allow no latitude, whereas imperfect duties, such as the duty of beneficence, require adopting an end but leave the agent discretion over when and how to act on it.

What is supererogation?

Supererogation refers to morally good acts, such as great self-sacrifice for others, that go beyond what duty strictly requires; they are praiseworthy to perform but not wrong to omit.

Duties and Obligations

Duties and obligations are the requirements morality places on agents, ranging from general duties owed to everyone to special obligations grounded in relationships, promises, and roles.

Definition

A moral duty or obligation is a requirement that an agent act or refrain from acting in a certain way; obligations may be general or special, perfect (owed determinately to assignable persons) or imperfect (latitude in fulfilment), and are distinguished from supererogatory acts that are good but not required.

Scope

This topic covers the structure of moral requirement: the distinction between perfect and imperfect duties, positive and negative duties, general and special obligations, and the contrast between what is obligatory, permissible, and supererogatory. It examines the sources of special obligations and the place of acts that go beyond duty, complementing the analysis of rights with the correlative notion of what agents must do.

Core questions

How do perfect duties differ from imperfect duties?
What grounds special obligations to particular people, such as family, friends, and co-nationals?
What is the relation between duties owed and the rights of others?
Are there morally good acts that go beyond what duty requires?

Key theories

Perfect and imperfect duties: Kant's distinction between perfect duties, which admit no exception in favour of inclination and are owed determinately, and imperfect duties, such as beneficence, which require adopting an end but leave latitude in how to act on it.
Supererogation: Urmson's argument that a complete moral theory must recognize a category of acts, the saintly and heroic, that are praiseworthy and good but exceed the demands of duty and so are not obligatory.

History

Kant (1797) systematized the division of duties into perfect and imperfect and into duties to self and others, while Ross (1930) catalogued a plurality of prima facie duties grounded in special relationships such as fidelity and gratitude. Urmson (1958) reopened the question of supererogation, arguing that the threefold scheme of forbidden, permitted, and obligatory omits acts beyond duty, a debate that continues today.

Debates

The grounds of special obligations: Whether special obligations to family, friends, and compatriots derive from voluntary undertakings, from the intrinsic value of relationships, or are reducible to general duties is widely disputed.
The paradox of supererogation: If a supererogatory act is morally best, it can seem puzzling that failing to perform it is permissible; explaining how the optional can be better than the required is a standing challenge.

Key figures

Immanuel Kant
W. D. Ross
J. O. Urmson
Samuel Scheffler

Seminal works

kant1797
ross1930
urmson1958

Frequently asked questions

What is the difference between perfect and imperfect duties?: Perfect duties, such as the duty not to make false promises, are strict requirements owed to assignable persons that allow no latitude, whereas imperfect duties, such as the duty of beneficence, require adopting an end but leave the agent discretion over when and how to act on it.
What is supererogation?: Supererogation refers to morally good acts, such as great self-sacrifice for others, that go beyond what duty strictly requires; they are praiseworthy to perform but not wrong to omit.