Definition
Ordinandi lex (Latin: "the law of ordering" or "the law of arrangement") is a civil-law phrase denoting the law of procedure — the body of rules governing how legal proceedings are conducted — as distinguished from the substantive law that defines rights, duties, and liabilities. Where substantive law answers the question "what are the parties' rights?", the ordinandi lex answers the question "by what process are those rights pursued and enforced?" The distinction maps roughly onto the modern division between procedural law and substantive law, though the Latin phrase itself belongs to the technical vocabulary of Roman and civil-law scholarship rather than to contemporary common-law usage.
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Common Confusion
All three source dictionaries append to their ORDINANDI LEX entry a maxim about the ORDINARY — "Ordinarius ita dicitur quia habet ordinariam jurisdictionem, in jure proprio, et non propter deputationem" (Co. Litt. 96: "The ordinary is so called because he has an ordinary jurisdiction in his own right, and not by deputation") — without clear typographic separation. This creates a real risk of confusion. The maxim about the ordinary is not a component of the definition of ordinandi lex. It is a separate entry or maxim placed immediately adjacent in alphabetical sequence. A researcher skimming historical dictionary sources should treat the two as distinct: ordinandi lex concerns procedural law; the maxim about the ordinary concerns ecclesiastical and probate jurisdiction. The confusion is compounded because Rapalje & Lawrence further appends a definition of the "Ordinary of Newgate" in the same breath, making the boundary between entries even less obvious.
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Why It Matters in Research
The primary research value of this term is taxonomic. Encountering ordinandi lex in a historical legal text — treatises, pleading manuals, civil-law commentaries, or conflict-of-laws discussions — signals that the author is invoking a substantive/procedural distinction that was doing significant analytical work long before modern procedural codes rationalized it.
In conflict-of-laws scholarship, the substantive/procedural distinction is not merely academic: it determines which jurisdiction's law governs. Courts historically applied the lex fori (the law of the forum) to procedural matters and the lex loci (the law of the place) to substantive ones. A text invoking ordinandi lex in that context is typically arguing that a particular rule is procedural and therefore governed by forum law rather than foreign law — a classification dispute with outcome-determinative consequences.
Researchers working in pre-twentieth-century American and English sources should be alert to the fact that the line between procedure and substance shifted considerably with the advent of the Field Code (1848), the English Judicature Acts (1873–1875), and ultimately the Federal Rules of Civil Procedure (1938). A treatise writer in 1820 invoking ordinandi lex may be drawing a boundary that a post-1938 court would draw very differently.
The term also appears in ecclesiastical and civil-law contexts where "the law of ordering" has a more literal institutional meaning — referring to the rules governing how a court or jurisdiction is constituted and administered, not merely the rules of practice. Context is essential to interpreting which sense is intended.
Finally, note the dictionary-presentation hazard described under COMMON CONFUSION above. Any citation to a historical dictionary definition of ordinandi lex should be verified against the actual page to confirm the researcher has captured the right entry and not inadvertently incorporated the adjacent maxim about the ordinary.
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Historical Dictionary Support
All three source dictionaries — Black's (1st and 2nd editions) and Rapalje & Lawrence — are in complete agreement on the core definition: ordinandi lex is the law of procedure as distinguished from the substantial part of the law. There is no divergence on substance.
What the dictionaries do not do is elaborate. None of them situates the phrase in the conflict-of-laws tradition where it most commonly functioned, nor do they explain its civil-law provenance or contrast it with the companion phrase lex judicandi (sometimes used for substantive law). The entries are definitional placeholders rather than analytical guides.
The appended Latin maxim about the ordinary (from Coke on Littleton, 96) appears verbatim across all three dictionaries, confirming that this was a standard cross-reference in the period's legal lexicography — not an editorial gloss added by any single compiler.
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Jurisdictional Note
Ordinandi lex as a working phrase is more native to civil-law systems and to English common-law writers trained in the civilian tradition. In American legal practice after the mid-nineteenth century, the phrase largely disappeared from operative legal writing, displaced by plain references to "procedural law," "adjective law," or "the law of remedies." Its appearance in American sources is almost exclusively in scholarly treatises and conflict-of-laws commentary.
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