This thesis examines the sources and method used by Sir James Dalrymple, 1st Viscount Stair, when writing and revising his seminal work, the Institutions of the Law of Scotland (1681). In doing so, it focuses particularly on Stair’s titles on the law of obligations. The thesis shows how Stair used learned authority and continental legal treatises. It demonstrates that Stair relied particularly upon Hugo Grotius’ De jure belli ac pacis (1625), Petrus Gudelinus’ De jure novissimo (1620), and Arnoldus Vinnius’ Commentarius academicus et forensis (1642), and, to a lesser extent, Vinnius’ Jurisprudentia contracta (1624-1631) and Arnoldus Corvinus’ Digesta per aphorismos (1642). It establishes when, in the process of writing and later revising the Institutions, Stair first used and when he returned to these continental legal treatises. It explains Stair’s pattern of borrowing from these treatises, and shows how his method and pattern of borrowing changed as he revised the Institutions. It establishes Stair’s purpose in consulting each of these works and how he was influenced by them. Overall, the thesis explains Stair’s method of writing and his use of sources and authorities, places his work in the context of continental jurisprudence, and thus significantly enhances current understanding of Stair’s Institutions.