The article explores the numerous aspects of the notion of res judicata, a veritably multi-faceted notion, and the manner in which these are dealt with in comparative law. The study first considers the less contested aspects of res judicata, and then explores the more uncharted territories of this notion. The principle of non bis in idem outlines a first circle of res judicata, a smaller common denominator between a Common Law jurisdiction such as England (which is marked by the principle of cause of action estoppel) and continental jurisdictions (where the principle of the negative or material authority of res judicata reigns: France, Germany, Belgium, Italy…). However this harmony hides various differences, resulting from a greater measure of tolerance under English law in the face of a res judicata defence: this is readily applied even though all aspects of the matter have not effectively been ruled upon, as a matter of law and fact.
These differences between the systems tend to increase even more when one draws a second,broader,circle corresponding to the positive dimension of the effects of res judicata, attributed to the reasons for a previous judgment (issue estoppel under English law), even if Civil law countries show signs towards the potential recognition of such positive effect.The divide even appears to become insuperable when a third and final circle is drawn — resulting from the Henderson v Henderson English law ruling. This stretches the doctrine of res judicata to its utmost limits by posing a principle of concentration of claims,which the laws of civil law jurisdictions continue to reject,subject to certain subtle distinctions:they remain loyal to the idea that res judicata can only apply to what has effectively been examined by the court.
Revue de l’arbitrage