shall see in his philosophy of the practical, between the economic and the ethical will. It is, however, not a mere logical form, or rather, it is a logical form, because it is the actual process of the spirit, which cannot either know or act except by forming a priori syntheses (æsthetic or logical, economic or ethical), that is, by constantly re-creating itself and its own reality and values. [Footnote 1: See _Logica_, part i, "Il concetto puro," etc., pp. 1-170.] VI. THE FORMS OF KNOWLEDGE[1] The elementary forms of knowledge--Philosophy as the pure concept-- Development of Croce's theory of history--The identity of history and philosophy--Subjectivity and objectivity--Distinctions and divisions of history--The historical determination of philosophy--The economic theory of science--The natural sciences--History and science--The naturalistic method and the concept of nature--Mathematical processes. The result of Croce's inquiry into the forms of man's theoretical activity can be summed up by saying that there are two pure theoretical forms, the intuition and the concept, of which the second can be subdivided for convenience' sake into the definition and the individual judgment; and two modes of the practical elaboration of knowledge, the empirical concept and the abstract concept, from which are derived the classificatory judgment and the judgment of numeration. Already in æsthetics we have found no rigorous criterion of distinction between the general intuitive activity of man, as it manifests itself in language, and those empirically constituted bodies of particular intuitions, which we call Poetry and the Arts: every man is a poet and an artist, though we reserve these names only for those among ourselves in whom the æsthetic activity manifests itself in a higher degree, dominates the whole life of the individual spirit. The concept and the pseudo-concepts are also elementary, fundamental forms of knowledge, of which all men partake: every man, as he is a poet, is also a philosopher and an historian, a scientist and a mathematician: but, again, we reserve these names only for the most conspicuous manifestations of those common spiritual activities, and form the empirical concepts of Philosophy and History, of Science and Mathematics. We may speak of vulgar knowledge and of pure or scientific knowledge, but only by approximation and without forgetting that the only claim to rationality and intelligibility on the part of pure knowledge lies in its relationship with the elementary forms, in the same way as Poetry owes its power and beauty to the language in which it spreads its roots. A particular treatment of these higher degrees of knowledge is not, therefore, logically justified; the problems that they present are the same that have been met with in the general discussion of the theoretical activity, and all they will have to offer will be but a confirmation, and in some points a clarification, of what has already been said.