In The Challenge of Comparative Literature Claudio Guillen describes his opinion on comparative literature in two parts. The first part is entitled The Emergence of Comparative Literature. While the second part is entitled Basic Issues. In part one, he explains the nationality, supra-nationality, internationality, universality, and unity of literature. Discussion on supranationality is written in chapter 10 of part one with the title Three Models of Supranationality. The first model is related with the study of phenomena and supranational assemblages that imply internationality. It suggests either genetic contacts or other relations between authors and processes belonging to distinct national spheres or common cultural premises. The second model is concerned with the phenomena or processes that genetically independent, or belong to different civilization. If the literary works containing such phenomena are collected and brought together to study, such an examination can be justified and carried out to the extent that common sociocultural conditions are implied. The third model describes that some genetically-independent phenomena make up supranational entities in accordance with principles and purposes derived from the theory of literature. This model has the highest grade of theoreticity, since the conceptual framework, instead of being pragmatic or merely adequate in the fact of the observable facts, usually provides a point of departure for investigation for the problem to be resolved. The theoretical framework suggests the statement of problem. But as the framework evolves, a contrary motion can begin, and new knowledge or some unpublished facts can challenge any theoretical notion.