The philosophical condemnation of artistic and literary classes is found in the formulation and demonstration of what artistic activity has ever sought and good taste ever recognized. What is to be done if good taste and the real fact, put into formulas, sometimes assume the air of paradoxes? [Sidenote] _Empirical sense of the divisions of classes._ Now if we talk of tragedies, comedies, dramas, romances, pictures of everyday life, battle-pieces, landscapes, seascapes, poems, versicles, lyrics, and the like, if it be only with a view to be understood, and to draw attention in general and approximatively to certain groups of works, to which, for one reason or another, it is desired to draw attention, in that case, no scientific error has been committed. We employ _vocables and phrases_; we do not establish _laws and definitions_. The mistake arises when the weight of a scientific definition is given to a word, when we ingenuously let ourselves be caught in the meshes of that phraseology. Pray permit me a comparison. It is necessary to arrange the books in a library in one way or another. This used generally to be done by means of a rough classification by subjects (among which the categories of miscellaneous and eccentric were not wanting); they are now generally arranged by sizes or by publishers. Who can deny the necessity and the utility of these groupings? But what should we say if some one began seriously to seek out the literary laws of miscellanies and of eccentricities from the Aldine or Bodonian collection, from size A or size B, that is to say, from these altogether arbitrary groupings whose sole object has been their practical use? Well, whoever should undertake an enterprise such as this, would be doing neither more nor less than those who seek out the aesthetic laws of literary and artistic classes. V ANALOGOUS ERRORS IN HISTORIC AND LOGIC The better to confirm these criticisms, it will be opportune to cast a rapid glance over analogous and opposite errors, born of ignorance as to the true nature of art, and of its relation to history and to science. These errors have injured alike the theory of history and of science, of Historic (or Historiology) and of Logic. [Sidenote] _Critique of the philosophy of history._