Sixteenth-century presumption theory.
A study of Jacopo Menochio’s De praesumptionibus (1587)

Based exclusively on primary sources, this study charts the reformulation of judicial proof in the late 16th c. following the introduction of the dualism of artificial/inartificial proofs in Jacopo Menochio’s treatise De praesumptionibus (1587). This study is a textual analysis of the theoretical section of this treatise and of the network of texts recalled by this work.

Although methodologically this is a strictly historical study, it shows the relevance of historical judicial proof (and broadly of the question of fact) to the formation of some basic legal categories (e.g. dualism fact/law, general category of contract, interpretation).

This study is meant to be a contribution to the growing field of historical epistemology.

Above pictured are the three (artificial) reasoning patterns shown in Petrus Victorius’ Commentary on Aristotle’s Rhetoric (1547): they generate a conclusion that is either necessary (fig. 1), probable by abduction (fig. 2) or probable by induction (fig. 3).

Jacopo Menochio borrowed the idea to produce a theory then transmitted by Natural lawyers to codifications. Some major legal doctrines produced in the late-16th century (dualism direct/indirect proofs, distinction law/fact, contract theory, interpretation) are grounded upon this rhetorical basis.