No acquisition of modern times is more remarkable than the nearer realization of the unity of spirit which pervades all research. Among a multitude of labourers in various fields of knowledge, there is a consciousness of a common aim, a common method, a common inspiration. This consciousness is no mere abstraction, but a living reality; the active pursuit of truth is a bond as strong as the bond of charity. And, while the widely-spreading love of truth is forming a new element of union among men, the objects of knowledge themselves are discovering more and more of their inner harmonies as their laws are read and verified by fresh experience. No branch of knowledge can now be seriously studied in isolation, or without a view to its actual or possible connexion with other branches, and the ultimate discovery of the simple principles underlying them all. This fact is obvious in the sphere of the humanities as well as in that of the natural sciences. Histories are studied for the sake of knowing history, languages for the sake of knowing language; and the studies of language and history are seen to be inseparably connected. Unities only guessed at or wrongly imagined before are disclosing themselves in their true aspect under the light of the comparative method. In this view it cannot be said of any ascertained set of facts that it is unfruitful or unworthy of further examination, or of any philosophical system, that it is final.