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Analogia Legis

Fill a genuine legal gap by extending the rule for a regulated case to an unregulated but relevantly similar case because the rule's justificatory reason applies to both.

Version
v2 · 2026-09-06 · History
Domain-specific #
1281
Origin domain
jurisprudence
Subdomain
civil-law methods and statutory reasoning
Aliases
Statutory analogy, Analogy from statute, Analogia legis

Core Idea

Analogia legis is a legal gap-filling method in which a rule governing one case is extended to an unregulated case because the reason that justifies the rule applies with relevant force to both. The source is a specific existing legal norm and its regulated case; the target is a case that the applicable law does not directly regulate; the warrant is not surface likeness but equality of legally material reason, often expressed as the ratio legis.

The operation is commonly represented as:

Scope of Application

Analogia legis recurs most visibly in civil-law systems whose codes or doctrine instruct courts how to integrate gaps. It operates across private law, procedure, administrative law, and other fields subject to different constraints. Portugal's Article 10 is a canonical codified example. Portuguese constitutional and supreme-court decisions repeatedly distinguish interpretation under Article 9 from gap integration under Article 10 and examine whether the source rule's justifying reasons extend to the omitted situation.

Clarity

An analogia-legis analysis becomes auditable through six questions.

  1. What exact proposition is missing? Identify the target consequence that no applicable rule directly supplies. 2. Why is the absence a gap rather than deliberate silence? Context, system, exceptions, and legislative design may show that omission was intentional. 3. Which source norm governs which source case? Quote or precisely identify the norm rather than invoking “similar law.” 4.

Manages Complexity

Legislation is necessarily finite, while fact patterns and institutional arrangements proliferate. Analogia legis lets a legal order address unforeseen or omitted cases without treating every silence as unbounded judicial discretion. It compresses a complex comparison into an explicit bridge from an existing rule's rationale.

The method also organizes disagreement. Parties may agree on the statute yet disagree about whether a gap exists, which source norm is closest, how its ratio should be framed, or whether a target difference is material.

Abstract Reasoning

The structure licenses several diagnostic inferences.

  • If ordinary interpretation directly covers the target, the issue is application or interpretation, not gap filling by analogy.
  • If the legislature addressed adjacent cases while conspicuously omitting the target, deliberate silence may defeat the premise of a lacuna.
  • If two cases share surface features but differ on the source rule's purpose, extension is unwarranted.
  • If the target shares the ratio more strongly than some cases expressly covered, equal-treatment pressure favors extension unless a prohibition controls.
  • If two plausible source norms point to incompatible consequences, the argument must explain why one ratio is more authoritative or specific.
  • If no particular source norm supplies a defensible comparison, moving to general principles changes the method toward analogia iuris.
  • If the consequence creates or aggravates criminal punishment, a legality rule may prohibit the move even when the similarity is strong.
  • If the proposed analogy undermines an explicit exception or closed enumeration, that system signal may show that the gap is intentional or nonextendable.
  • If the source rule is amended or repealed, the analogy's foundation changes even when the factual resemblance remains.

Knowledge Transfer

The method transfers literally among legal fields and jurisdictions only when each system's positive-law controls are re-established. A jurist can carry the questions “Is there a gap?”, “What source norm?”, “What ratio?”, and “Which differences matter?” from contract law to procedure or administrative law. The roles remain stable even though the permissions and consequences change.

It also transfers between drafting and adjudication. Legislators can examine judicial analogies to discover recurring omissions; courts can use a new amendment as evidence that earlier silence was intentional or accidental.

Relationships to Other Abstractions

Local relationship map for Analogia LegisParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Analogia LegisDOMAINPrime abstraction: Analogy — is a kind ofAnalogyPRIME

Current abstraction Analogia Legis Domain-specific

Parents (1) — more general patterns this builds on

  • Analogia Legis is a kind of Analogy Prime

    Analogy is the minimal prospective parent.

Hierarchy paths (2) — routes to 2 parentless roots

Neighborhood in Abstraction Space

Analogia Legis sits in a sparse region of the domain-specific corpus (93rd percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (1565 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-09-08