The interface between competition law and private law: Article 81, illegality and unjustified enrichment

By and large, it remains true that Scots law distinguishes contract and unjustified enrichment, and modern work in the two fields continues to reflect this. Although the third edition of Professor Walker's work on contract (1995) retains its final chapter on "obligations arising from unjust enrichment", the editors of the tenth edition (also 1995) of Gloag and Henderson, the standard introductory work on Scots law, have retitled as "Unjustified Enrichment" the chapter known in previous editions as "Quasi-Contract", and it has been moved from its previous position within the treatment of the general law of contract to a much later and completely separate treatment alongside salvage. William Stewart's Law of Restitution in Scotland (1992), the first book-length treatment of the subject, scrupulously leaves contract law out of consideration. Volume 15 of the Stair Memorial Encyclopedia, which deals with the Scots law of obligations and was published in 1996, distinguishes the voluntary obligations of contract and promise from obligations imposed by force of law and obligations arising from a wrongful act, and includes unjustified enrichment and negotiorum gestio in the second category.