Literary criticism, which until fifty or sixty years ago, stood only for the judgment and valuation of literary works, to-day usually includes, beside the æsthetic valuation, the study of the historical development, the edition and comment of the text, the biography of the author, the exposition of the work itself, the æsthetic theory of literature, and so on; in fact, every kind of conceivable work on literature. The danger of this extension of meaning lies in the facility with which we are led to believe that many things, when called with one name, are really one thing: we think of literary criticism as of the synthesis of all the above-mentioned operations--a synthesis which, as Croce observes, when it exists cannot be due to anybody but the printer. Or, again, we may consider that one or another of those operations is the true aim of literary criticism--and to that one we subordinate all the others, as merely subservient to the particular aim we have in sight. This is the origin of the various _schools_ of criticism--æsthetic, historical, psychological--each of which believes itself to be in possession of the only legitimate method. But if we subordinate the history of a work to its æsthetic valuation, we deny the independence and intrinsic importance of history; if we subordinate the æsthetic valuation to the historical consideration, we make of the former a useless accessory of the latter; if we subordinate the biography of the author to the historical explanation of the work, we destroy the importance of biography, which, though useful in a certain sense to the explanation of the work, is in itself "nothing but the history of the development of a moral personality."[1] In fact, the unity of literary criticism lies not in its aim, but in its subject-matter: what we mean by literary criticism is "a series of particular operations having independent aims, without any other connection than that of the material employed in each of them."[2] Croce does not deny the possibility of using the results of one of these operations for the purposes of another, but this does not change the nature of either: "the spirit of man is not divided into small compartments: all our experience helps us in whatever work we are doing. To understand Petrarch's poetry, it is useful either to be or to have been in love; but it doesn't follow that to make love and to understand that poetry are one and the same thing."[3]