critically with literary documents on which no critical work has as yet been done without making oneself familiar with the results obtained by those who have already dealt critically with documents of the same class: the sum of these results forms a department to itself, which has a name—the History of Literature. The critical treatment of illustrative documents, such as the productions of architecture, sculpture, and painting, objects of all kinds (arms, dress, utensils, coins, medals, armorial bearings, and so forth), presupposes a thorough acquaintance with the rules and observations which constitute Archæology properly so called and its detached branches—Numismatic and Heraldry.
We are now in a position to examine to some purpose the hazy notion expressed by the phrase, "the sciences auxiliary to history." We also read of "ancillary sciences," and, in French, "sciences satellites." None of these expressions is really satisfactory.
First of all, the so-called "auxiliary sciences" are not all of them sciences. Diplomatic, for example, and the History of Literature are only systematised accumulations of facts, acquired by criticism, which are of a nature to facilitate the application of critical methods to documents hitherto untouched. On the other hand, Philology is an organised science, and has its own laws.
In the second place, among the branches of knowledge auxiliary—properly speaking, not to history, but to historical research—we must distinguish between those which every worker in the field ought to master, and those in respect of which he needs only to know where to look when he has occasion to make use of them; between knowledge which ought to become part of a man's self, and information which he may be content to possess only in potentiality. A mediævalist should know how