COMMUNIS OPINIO

communis opinio (k<<schwa>>-myoo-nis <<schwa>>-pin-ee-oh). [Latin “common opinion”] Hist. A generally accepted belief about a point of law. • If held unanimously by those learned in the law, this common belief had the force of law in classical Rome.

“Communis opinio is evidence of what the law is, — not where it is an opinion merely speculative and theoretical, floating in the minds of persons, but where it has been made the ground-work and substratum of practice.” 1 Alexander M. Burrill, A Law-Dictionary and Glossary 330 (2d ed. 1867) (quoting Lord Ellenborough). [Blacks Law 8th]