Columbia subject headings:
Obligations (Roman law)
Quasi contracts (Roman law)
Slavery (Roman law)
Harvard subject headings:
Compensation (Roman law)
Inheritance and succession (Roman law)
Natural obligations (Roman law)
Seneca, Lucius Annaeus, approximately 4 B.C.-65 A.D. De beneficiis.
Serfdom (Roman law)
Slavery (Roman law)
Princeton subject headings:
Compensation (Roman law)
Natural obligations (Roman law)
Serfdom (Roman law)