Definition
Latin: "Between the dog and the wolf." A legal term of art referring to the twilight hour — the period of dim, ambiguous light between daylight and full darkness. The phrase captures the moment when illumination is so uncertain that a dog cannot reliably be distinguished from a wolf.
In historical legal usage, the phrase served as a precise temporal marker. Because many legal rights and obligations — the execution of instruments, the lawfulness of certain acts, the running of deadlines — could turn on whether something occurred during daylight or after dark, courts and practitioners needed language to describe the ambiguous boundary between the two. Inter canem et lupum named that boundary.
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Common Language
This is pure Latin legal terminology with no counterpart in ordinary modern English. The phrase survives in common usage only as an occasional literary or poetic description of twilight. No COMMON LANGUAGE section applies.
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Why It Matters in Research
Researchers will encounter this phrase almost exclusively in pre-modern legal materials — English common law treatises, Year Books, glossaries of Latin maxims, and texts drawing on civil and canon law tradition. It is not a term of art in contemporary legal drafting or judicial opinions.
The primary research trap is treating the phrase as merely decorative Latin when it may carry genuine temporal legal weight in the document being examined. Historically, the distinction between daylight and darkness was legally operative in numerous contexts: the unlawfulness of certain arrests or entries made after dark; the rule that burglary required the act to occur in the nighttime; the validity of witnessing instruments before versus after light failed. When inter canem et lupum appears in a historical source, it signals that a legal actor was addressing precisely that contested threshold — not simply invoking poetic atmosphere.
The phrase also illustrates a broader feature of pre-modern legal Latin: natural phenomena and observable physical conditions were frequently used to anchor temporal or factual standards that modern law resolves by clock or statute. Researchers working in medieval or early modern materials should recognize this terminological pattern across similar phrases.
Note the discrepancy between the two Black's editions: the first edition cites Coke's Institutes at page 63, the second at page 68. This reflects a common pagination variance between printings of Coke and should not be read as a substantive difference in the underlying authority.
The second edition of Black's appends an entirely separate definition connecting the phrase to disinheritance clauses in Roman civil law (Justinian's Institutes 2.13.1 and 2.13.3). This is a distinct usage with no apparent connection to the twilight meaning and appears in neither the first Black's edition nor Burrill. Researchers should treat this as a possible editorial interpolation or a separate term that shares the same Latin string by coincidence or transcription error. Caution is warranted before treating the two meanings as related.
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Historical Dictionary Support
All three source dictionaries agree on the core twilight meaning and its underlying rationale: the light of that hour is so uncertain that a dog cannot be told from a wolf. Burrill is the most precise on the visual logic, quoting the Latin gloss cum lupus à cane non fit cognoscibilis ("when a wolf cannot be distinguished from a dog") and citing Spelman and Cowell as underlying authorities, making it the most useful starting point for tracing the phrase's provenance.
Black's first and second editions both cite Coke's Institutes (Third Institute) as authority, anchoring the phrase in English common law reception of earlier legal tradition. Burrill traces through Spelman's Glossarium and Cowell's Interpreter, pointing toward an earlier antiquarian legal lexicography lineage.
The anomalous disinheritance meaning appearing only in Black's second edition, attributed to Justinian's Institutes, remains unexplained by any of the three source dictionaries. No synthesis across these sources resolves the discrepancy, and no source offers a bridge connecting the twilight usage to the civil law inheritance context. A researcher who encounters only the second edition of Black's may be misled into believing both meanings are equally established. They are not.
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Jurisdictional Note
This phrase carries no jurisdiction-specific variation in modern law. Its significance is almost entirely historical and confined to materials predating systematic statutory definitions of "nighttime" and similar temporal standards.
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