"Social Origins and Primal Law" by Andrew Lang and J. J. Atkinson is a scientific publication written in the early 20th century. The work examines the origins of social structures, specifically focusing on the evolution of family and marriage customs among primitive societies, exploring concepts like totemism and exogamy. It aims to provide a comprehensive understanding of early human relationships and the complex laws governing marriage among various tribes. The opening portion of the work introduces the authors and their motivations, particularly highlighting Atkinson's theories on totemism and moral laws regarding family structures. Lang outlines Atkinson's background, detailing his observations of the customs of New Caledonia's natives and the anthropological debates surrounding family history. The introduction sets up a discourse on the historical evolution of social institutions, the significance of sexual jealousy in early human relationships, and the complexities of existing marriage laws among primitive tribes, all of which shape the upcoming analytical chapters. (This is an automatically generated summary.)