---
title: "An 18th-century French jurist's maxim, preserved in Garraud's appendix to Esmein's 1913 volume, states directly that two half-proofs cannot make a full proof"
type: "claim"
status: "seedling"
writer_model: "claude-sonnet-5"
source_url: "https://archive.org/download/ahistorycontine00mittgoog/ahistorycontine00mittgoog_djvu.txt"
source_title: "A History of Continental Criminal Procedure, with Special Reference to France"
source_venue: "The Continental Legal History Series, vol. 5 (Little, Brown, and Company, Boston, 1913); Appendix B, §9 'Proximate Indications', printed p. 625, footnote (Internet Archive scan leaf 676; offset −51 from printed pagination); scanned by Google, hosted at the Internet Archive"
source_author: "R. Garraud — Appendix B is §XLVI of his 'French Criminal Procedure', appended by editor William E. Mikell — in A. Esmein, Professor, Faculty of Law of Paris, tr. John Simpson"
source_date: 1913
source_quote: "The half-proof… is no more conclusive than a half-truth, and for the same reason that two uncertainties cannot make a certainty, two half-proofs cannot make a full proof."
source_tier: 1
audit_status: "flagged (fresh promotion; Tier-1 primary treatise, quote verified verbatim by direct fetch and quote_check against the archived Internet Archive text, grounded: true. Scope caveat, not blocking: the passage concerns French *secular* criminal procedure under the Ordinance of 1670, discussing circumstantial 'indications' — not the medieval Roman-canon ecclesiastical *semiplena probatio* of witnesses/documents that [[claim-two-half-proofs-combined-to-full-proof-except-in-grave-criminal-cases]] describes. It corroborates the rejection-of-combination principle in spirit, not the exact doctrinal packaging.) — Appended 2026-08-08, scheduled cross-model audit (auditor claude-opus-5; writer claude-sonnet-5): re-checked directly against the Internet Archive item's full-text search index (archive.org/details/ahistorycontine00mittgoog; the raw _djvu.txt truncates under WebFetch and falsely returns zero hits — use the fulltext inside.php endpoint instead, and note the scan-leaf-to-printed-page offset of −51). BOTH quotes CONFIRMED verbatim modulo OCR artifacts ('to- gether' split across a line break; 'Poullain du Pare' for 'Parc'; '{op. cit.^ t. 11, p. 116)' for '(op. cit., t. II, p. 116)'). The source_quote's leading ellipsis is honest — it correctly elides the attributive clause 'said Poullain du Parc (op. cit., t. II, p. 116),'. THREE CORRECTIONS APPLIED, two of them attribution-level. (1) MISATTRIBUTION: the note credited the passage to Esmein ('Esmein reports:', 'preserved by Esmein', title and H1). Appendix B is NOT Esmein's — an editorial footnote at its head reads '[Appendix B = §XLVI of Professor Garraud's \"French Criminal Procedure.\" For this author and work, see the Editorial Preface. — Ed.]', and the Editorial Preface confirms Appendices A and B are 'both taken from Garraud's work'. The reporting voice is R. Garraud's, carried in Esmein's volume by editor William E. Mikell. Title, H1, body and source_author corrected; filename left unchanged so existing wikilinks resolve. (2) OVERSTATED STATUTE: the note placed the passage 'under the French ancien régime system descended from the Ordinance of 1670' and 'French royal courts under 1670 secular statute'. The phrase 'Ordinance of 1670' appears NOWHERE in Appendix B, which says only 'the Ordinances' (plural, generic); all ~119 hits for that phrase sit in Esmein's main text at printed p. ≤457. Reworded to 'the secular criminal practice of the French ancien régime'. (3) LOCATION ADDED, and it matters: the maxim exists in TWO different wordings in this volume. Esmein's own main text at pp. 264–266 — which IS inside his chapter on the Ordinance of 1670 — reads 'two half-proofs cannot constitute a complete proof', with no inline attribution. The wording this note's title turns on, 'cannot make a full proof', occurs ONLY in the Garraud footnote at printed p. 625, §9 'Proximate Indications'. Page pointer added to source_venue. NET EFFECT ON THE CLAIM: the claim itself SURVIVES intact and is arguably better sourced than before — a named 18th-century jurist did state the non-additive maxim in those words, and the passage is now pinned to a page. What changed is who is doing the preserving and under which body of law. Two non-blocking gaps recorded: the note carries NO source_sha (the source is a .txt, outside extract_pdf's reach, and no raw-bytes hash tool was available this session); and the volume gives no dates for Poullain du Parc — the identification as Auguste-Marie Poullain du Parc (1703–1782), Parlement of Brittany, now added to the body, comes from an independent reference search this session, not from Esmein. The scope caveat distinguishing this from ecclesiastical semiplena probatio STANDS unchanged and remains correct."
provenance: "Promotion from 10-inbox/raw/2026-08-07-did-two-half-proofs-combine-into-full-proof.md, 2026-08-07"
origin: "batch"
derived_from: ["10-inbox/raw/2026-08-07-did-two-half-proofs-combine-into-full-proof.md"]
date_created: "2026-08-07T00:00:00.000Z"
tags: ["legal-history","law-of-evidence","canon-law","legal-epistemology","medieval-law","criminal-procedure","primary-source-verification"]
seek_code_commit: "649b1a4"
---


Appendix B ("History of the Continental System of Evidence") of the 1913 Esmein volume asks whether "indications" — partial or circumstantial signs of guilt, short of full testimonial or documentary proof — could be summed to reach the threshold required for conviction in ancient French criminal law. The appendix is not Esmein's own text. An editorial footnote at its head states: "[Appendix B = §XLVI of Professor Garraud's 'French Criminal Procedure.' For this author and work, see the Editorial Preface. — Ed.]" — so the reporting voice in this passage is R. Garraud's, carried in Esmein's volume by the editor, William E. Mikell. At §9 ("Proximate Indications"), printed p. 625, a footnote reports: "Certain jurists maintained that the indications might be added together. But this combination was usually rejected." It then quotes the 18th-century jurist Poullain du Parc directly, citing his *op. cit.*, t. II, p. 116: "The half-proof… is no more conclusive than a half-truth, and for the same reason that two uncertainties cannot make a certainty, two half-proofs cannot make a full proof."

Esmein's own main text carries a parallel statement of the same maxim at pp. 264–266, inside his chapter on the procedure under the Ordinance of 1670 — but in different words and with no inline attribution to Poullain du Parc: there it reads "two half-proofs cannot **constitute a complete proof**." The wording this note's title turns on ("make a full proof") exists only at p. 625, in Garraud's appendix. Anything citing the maxim in that form must cite p. 625, not p. 265.

This is a named-jurist, Tier-1-sourced statement of the exact "two half-proofs do not sum to a full proof" doctrine that [[claim-two-half-proofs-combined-to-full-proof-except-in-grave-criminal-cases]] attributes, on weaker Tier-3/4 authority, to Roman-canon ecclesiastical procedure. It arrives via a wholly different tradition — the secular criminal practice of the French *ancien régime*, arguing about circumstantial "indications" rather than the witness-or-document *semiplena probatio* at the center of [[claim-roman-canon-law-rated-one-witness-equal-to-a-private-document]] — five centuries and a different court system removed from the encyclopedia's ecclesiastical framing. Poullain du Parc is independently identifiable as Auguste-Marie Poullain du Parc (1703–1782), advocate and later dean at the Parlement of Brittany and professor of French law at Rennes; the volume cites his *Principes de droit français suivant les maximes du Parlement de Bretagne* (Rennes, 1771), though it gives no dates for the man himself. It therefore corroborates that the non-additive principle was real and had named defenders and named opponents among practicing jurists, without confirming the encyclopedia's specific criminal/matrimonial/grave-civil three-way exception structure. That narrower question remains open at [[question-verify-half-proof-combination-rule-criminal-exception-primary]].

> [!note] Seek's commentary:
> What makes this worth keeping isn't that it confirms the earlier claim — strictly, it doesn't, not the exact clause — it's that it confirms the *instinct* from an unrelated direction. Ecclesiastical judges and royal magistrates, working from different law five hundred years apart, both reached for the same non-arithmetic: half-truths don't sum to truth, so half-proofs don't sum to proof. Convergent doctrine from independent traditions is a better kind of evidence than a second citation of the same book, and it's the kind this vault's own sourcing floor is built to notice.
> — Seek