Definition
Similitude, in legal usage, refers principally to the doctrine of constructive or implied classification in customs and tariff law: when an imported article is not expressly enumerated in a tariff schedule, it is assessed duties at the rate applicable to the most similar enumerated article. The doctrine holds that like goods should be treated alike for duty purposes, even when the legislature has not specifically named every conceivable product.
More broadly, similitude appears in legal writing as a general term for resemblance or likeness between things — used in analogical reasoning, statutory construction, and occasionally in equity — but the customs law application is the term's primary technical legal meaning.
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Common Language
Modern common usage (Wiktionary): Similarity or resemblance to something else; also a parable, allegory, or a mathematical transformation preserving angles and distance ratios.
Historical common usage (Webster's 1913): "The quality or state of being similar or like; resemblance; likeness; similarity." Webster's also records the rhetorical sense — a fanciful or imaginative comparison, a simile — citing Milton and Pope.
The gap between common and legal meaning is narrow in spirit but significant in application. Ordinary usage treats similitude as a descriptive quality — two things are alike. The legal doctrine of similitude is operative: it is a rule of decision that compels a specific legal consequence (tariff classification) from that likeness. A researcher who treats the legal term as merely descriptive will miss the structured classificatory function it performs in customs adjudication.
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Common Confusion
Similitude is sometimes conflated with analogy or ejusdem generis in statutory construction discussions. They are related but distinct. Ejusdem generis limits the reach of a general term at the end of a specific list by reference to the character of listed items. Similitude in customs law is a freestanding classification rule: it applies when an article falls entirely outside a schedule, not merely when a general catch-all clause is ambiguous. The similitude doctrine also carries a distinct procedural posture — it is triggered by the absence of any enumeration, not by competing enumeration.
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Why It Matters in Research
Researchers working in nineteenth and early twentieth century customs and tariff materials will encounter similitude as a formal legal doctrine with a specific statutory home in successive U.S. tariff acts. The doctrine was codified in various forms in American tariff legislation from the mid-1800s onward, requiring that unenumerated articles be classified by reference to enumerated articles of similar composition, use, or character. Understanding that similitude is a term of art in this context — not merely an ornamental word for resemblance — is essential for reading customs tribunal decisions correctly.
In older legal writing outside customs law, similitude appears in analogical reasoning and equity arguments where courts justified extending a rule to a situation not squarely covered by precedent. This usage is looser and more rhetorical; researchers should not import the precision of the customs doctrine into those contexts.
Trap for historical researchers: Anderson's Dictionary of Law does not contain a standalone entry for similitude as a customs doctrine. The absence of explicit coverage in period dictionaries can mislead a researcher into treating the term as purely descriptive when encountered in customs opinions. The doctrine was well-established in practice and statute even where dictionary compilers did not treat it as a discrete headword.
Jurisdictional note: The similitude doctrine in its formal statutory form is primarily a feature of American federal customs law. English and Commonwealth tariff practice developed parallel classificatory mechanisms but did not consistently use similitude as the governing term.
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Historical Dictionary Support
Anderson's Dictionary of Law does not supply a standalone entry for similitude in the legal-technical sense. The source material provided for this entry concerns reservation and reserve — apparently a retrieval anomaly — and does not bear on the term. Researchers should note this gap: Anderson's silence on similitude as a customs doctrine reflects the tendency of late nineteenth century law dictionaries to underrepresent administrative and tariff law vocabulary relative to common law terms.
Webster's 1913 captures the rhetorical and philosophical senses well — resemblance, likeness, simile — and its examples from Milton and Tasso illustrate the literary register in which the word also appears in older legal writing. What Webster's does not address is the operative legal function of similitude in tariff classification, which had by 1913 already accumulated substantial decisional law in American customs courts. The mathematical sense (a Euclidean transformation preserving angles and distance ratios) recorded in Wiktionary is entirely foreign to legal usage and should be disregarded in legal research contexts.
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Jurisdictional Note
The similitude doctrine as a formal tariff classification rule is a creature of U.S. federal statutory law and customs jurisprudence. Researchers working in comparative trade law should not assume a direct equivalent in other national systems, though the underlying principle — that unenumerated goods must be classified by reference to their nearest enumerated analog — appears in various forms across tariff regimes and in WTO classification practice.
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Encyclopedia Cross-Reference
Law Mind Encyclopedia — Customs and Tariff Law (primary reference for the classification doctrine and its statutory history)
Law Mind Encyclopedia — Statutory Interpretation (for the analogical reasoning and ejusdem generis connections)
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