Half-proof

{{Short description|Concept in medieval Roman law}} '''Half-proof''' ({{lang|la|semiplena probatio}}) was a concept of medieval Roman law, describing a level of evidence between mere suspicion and the full proof ({{lang|la|plena probatio}}) needed to convict someone of a crime. The concept was introduced by the Glossators of the 1190s such as Azo, who gives such examples as a single witness or private documents.<ref name=Frabook>{{cite book |last=Franklin |first=James |author-link=James Franklin (philosopher) |date=2001 |title=The Science of Conjecture: Evidence and Probability Before Pascal |url=https://books.google.com/books?id=1zDECQAAQBAJ |location=Baltimore |publisher=Johns Hopkins University Press |page=18-19 |isbn=0-8018-6569-7}}</ref>

In cases where there was half-proof against a defendant, he might be allowed to take an oath as to his innocence, or he might be sent for torture to extract further evidence that could complete the burden of proof.<ref name=Frabook />{{rp|26-27, 59}}

Sir Matthew Hale, the leading late 17th-century English jurist, wrote:{{quote|The evidence at Law which taken singly or apart makes but an imperfect proof, {{lang|la|semiplena probatio}}, yet in conjunction with others grows to a full proof, like Silurus his twigs, that were easily broken apart, but in conjunction or union were not to be broken.<ref>B. Shapiro, ''Probability and Certainty in Seventeenth-Century England'', Princeton, 1983, p. 180.</ref>}}

However, the concept never became firmly established in English law.

Voltaire claimed that the Parlement of Toulouse dealt not only in half-proofs but in quarter-proofs and eighth-proofs,<ref>{{cite book |last1=Beccaria |first1=Cesare |last2=Voltaire |first2=François-Marie Arouet |date=1872 |title=An Essay on Crimes and Punishments. By the Marquis Beccaria of Milan. With a Commentary by M. de Voltaire |url=https://oll.libertyfund.org/title/voltaire-an-essay-on-crimes-and-punishments#lf1476_label_151 |location=Albany, NY |publisher=W.C. Little |chapter=XXII |isbn=}}</ref> but there is no direct evidence of that.{{fact|date=June 2025}}

In later times, half-proof was mentioned in 19th century Scots law<ref>J. Erskine, ''An Institute of the Law of Scotland'', ed. J. Ivory, Edinburgh, 1828, II: pp. 965, 972.</ref> and in the 1917 Catholic Code of Canon Law.<ref name=Frabook />{{rp|369}}

==References== {{reflist}}

==External links== * [https://www.law-dictionary.org/definitions-h/half-proof.html Law Dictionary entry, Half proof]

{{DEFAULTSORT:Half-Proof}} Category:Criminal law Category:Evidence law Category:Medieval law