Definition
DUTIES carries two distinct legal meanings that operate in largely separate doctrinal worlds:
1. Fiscal/Revenue Sense. Taxes, imposts, or charges levied by a government on persons, goods, or transactions. In its narrowest and most common usage, duties refers specifically to customs — charges imposed on goods at the point of import or export. In its broader fiscal sense, the word can encompass any governmental imposition or levy, including excise charges, making it nearly synonymous with taxes generally.
2. Obligations Sense. The plural of duty — legal or equitable obligations owed by one person (or legal entity) to another. These arise from contract, tort, statute, fiduciary relationship, or common law. In this sense, duties describes the bundle of affirmative or negative obligations that legal actors carry: a director's fiduciary duties to shareholders, a contractor's duties of performance, an insurer's duties to defend and indemnify.
Common Language
Modern common usage (Wiktionary): Plural of duty — general obligations, taxes, or tasks assigned to a person.
Historical common usage (Webster's 1913): Duties encompassed both moral obligations owed to others and taxes or tolls imposed by law, particularly on imported goods.
The common usage is broad enough to straddle both legal meanings, but the gap lies in precision. Ordinary speakers use "duties" loosely for any responsibility or obligation. Legal usage, however, treats the fiscal and obligational senses as categorically distinct — one belonging to constitutional and revenue law, the other to contract, tort, and fiduciary doctrine. Conflating them in legal research produces entirely different bodies of authority.
Recognized Forms
/SUBTYPES
Fiscal duties:
— Import duties (customs): charges on goods entering a jurisdiction
— Export duties: charges on goods leaving a jurisdiction
— Excise duties: charges on goods produced or consumed domestically
— Ad valorem duties: calculated as a percentage of the good's value
— Specific duties: charged at a fixed rate per unit of quantity or weight
— Duties ad gross: payment in gross based on estimated amount, subject to final liquidation and lawful deductions
Obligational duties:
— Fiduciary duties: duties of care, loyalty, good faith, and oversight arising from a relationship of trust (directors, trustees, agents)
— Contractual duties: obligations created by agreement, including duties of performance, delegation, and non-delegation
— Duties to defend and indemnify: distinct insurance obligations, often triggered at different thresholds
— Statutory duties: obligations imposed directly by legislation, the breach of which may sound in negligence per se
Why It Matters in Research
The central trap for corpus researchers is that DUTIES is a homograph — the same word indexes two largely non-overlapping bodies of law. A search on "duties" in constitutional or revenue law materials will surface fiscal impost doctrine; the same search in corporate, contracts, or tort materials will surface obligation doctrine. Know which world you are in before running broad searches.
In historical sources, the fiscal sense dominates. Constitutional-era materials — founding documents, early treatises, Story's Commentaries — use "duties" almost exclusively in the revenue context. Researchers working on 18th and early 19th century sources should not assume that "duties" signals any obligational meaning.
The obligational sense becomes increasingly prominent through the 19th century as equity and contract doctrine matured, and it dominates 20th and 21st century corporate and insurance law literature. The emergence of fiduciary duty doctrine — particularly the elaboration of directors' duties following the development of the business judgment rule — makes "duties" central to modern corporate law research in ways that have no counterpart in the founding-era fiscal usage.
Watch also for the duties/rights pairing in legal philosophy and analytical jurisprudence (Hohfeld, the rights-duties correlative). That usage overlaps with but is not identical to either the fiscal or the fiduciary sense.
Jurisdictional variation in the fiscal sense is significant for trade and tariff research: federal constitutional authority over import and export duties is exclusive (U.S. Const. art. I), while state taxing power operates under a different framework. In the obligational sense, fiduciary duties vary meaningfully by state corporate law — Delaware doctrine on director duties is not universal.
Historical Dictionary Support
The historical dictionaries align closely on the fiscal definition. Black's (both editions), Bouvier's, and Burrill's all describe duties as, in the broadest sense, nearly equivalent to taxes generally, and in the more restrained sense, equivalent to customs or imposts. The formulation tracks Story's Commentaries on the Constitution, which all three sources cite directly or indirectly. This convergence is itself significant: in the revenue law tradition, the meaning of duties was well-settled enough that major dictionaries could simply cross-reference Story.
What the historical dictionaries miss almost entirely is the obligational sense. Burrill's nod to "rights due from persons" with a citation to Blackstone's Commentaries is the closest any of these sources comes to the fiduciary or contractual meaning — and it is brief to the point of dismissal. This is not a gap in the dictionaries so much as a reflection of when they were written: the elaborate apparatus of modern fiduciary, insurance, and corporate duty doctrine postdates these texts substantially. Researchers relying solely on historical dictionary support for "duties" in an obligational context will find it nearly useless and should move directly to treatises and primary sources in equity and contract.
Jurisdictional Note
Federal power over import and export duties is constitutionally exclusive; states may not impose duties on imports or exports beyond what Congress permits. In the obligational sense, fiduciary duties owed by corporate directors are governed primarily by state corporate law, and the content of those duties — particularly the relationship between the duty of care, duty of loyalty, and duty of good faith — varies across jurisdictions, with Delaware's framework most frequently treated as the reference point in national scholarship.