The Cambridge History of English and American Literature in 18 Volumes (1907–21). Volume XIV. The Victorian Age, Part Two. I. Philosophers. § 25. Maine’s Ancient Law. The transformation of the biological sciences by the theory of evolution was connected with a wider movement, which consisted in the greatly extended use of the historical method in explaining the nature of things. This applies chiefly to the social sciences. It is to be remembered that both Darwin and Wallace owed the suggestion of their hypothesis of natural selection to a work on social theory. The underlying doctrine, was, simply, that facts were to be understood by tracing their origins and historical connections. How far this historical understanding could take the enquirer became the point at issue between what may be called the evolution philosophy and its critics: it may be expressed in the question whether or not origin determines validity. It was only gradually, however, that the point of controversy became clear; and, mean-while, the application of the historical method vastly aided the understanding of the social order. In this reference, the treatise entitled Ancient Law (1861) by Sir Henry Maine marks an epoch in the study of law and institutions, and it had a much wider influence upon thought generally by furthering the use of the method which it employed. An early example of the application of the same method in economics may be found in the series of essays by Thomas Edward Cliffe Leslie, republished as Essays in Political Economy (1888); and the historical side of economics has subsequently been exhaustively worked.   56