Private Law Theory

ABSTRACT
Unjust enrichment exists in both civil law and common law jurisdictions. The principle of unjust enrichment is widely seen in the prohibition to benefit from another’s loss, as first formulated by the classical Roman jurist Sextus Pomponius: nemo cum alterius detrimento locupletior fieri debet (D.12.6.4). But in the 19th century, the German jurist Friedrich Carl von Savigny found a more precise basis of all ‘true’ enrichment claims in the reversal of a unmittelbare Vermögensverschiebung (direct shift of value/wealth) that had taken place ohne Rechtsgrund (without legal ground). The alternative principle leads to a ‘narrow’ law of unjust enrichment on a persuasive normative basis. It arguably sits better with common law than the ‘wide’ unjust enrichment under the equitable Pomponian principle that induces ‘sloppiness of thought’.

Schall, Alexander, The Principle of Unjust Enrichment (January 16, 2024).