I would like to make several points in this essay. First, the historians of national legal systems are still, by and large, balkanized. They study, explain, and trace the history of their legal systems with only a cursory nod in the direction of the Ius commune. Second, within the Ius commune, some historians still approach a topic as if its various parts can be studied in isolation. A Romanist will study a doctrine of Roman law as if canon and feudal law had only tangential influence on the development of the thought of the civilians.
Kenneth Pennington, Learned Law, Droit Savant, Gelehrtes Recht: The Tyranny of a Concept, 20 SYRACUSE J. INT’L L. & COM. 205 (1994).