Abstract
Contrary to a widespread view in English historiography, the law of evidence, and in particular the law of testimony, existed in common law before the 18th or 19th century, and owes its existence not so much to the specific features of the legal system in question as to fundamental considerations regarding the nature of evidence and its modes, under the undeniable if unacknowledged influence of the techniques of Romano-Canonical procedure. After an overview of the subject, we'll use a specific example - that of the prohibition of opinion evidence - to show why learned law is the source of the rule, but also how the logic of common law changes its regime.
