Explanation:

Allen. Historical jurisprudence examines the manner or growth of legal system, and traces the growth of law from origin with a view to finding out the origin of our legal concepts and the general course of their evolution. It deals with the general princi­ples governing the origin and development of law as also the origin and development of legal conceptions and principles found in the philosophy If law.

According to Allen, “the historical movement in jurisprudence may be called the revolt of fact against fancy