Now, the five Aesthetics so far mentioned are not referable to contingent facts and historical epochs, as are, on the other hand, the denominations of Greek and Mediaeval Aesthetic, of Renaissance and eighteenth-century Aesthetic, the Aesthetic of Wolff and of Herbart, of Vico and of Hegel. These five are, on the contrary, mental attitudes, which are found in all periods, although they have not always conspicuous representatives of the kind that are said to become historical. Empirical Aesthetic is, for example, called Burke in the eighteenth, Fechner in the nineteenth century; moralistic Aesthetic is Horace or Plutarch in antiquity, Campanella in modern times; intellectualist or logical Aesthetic is Cartesian in the seventeenth, Leibnitzian in the eighteenth, and Hegelian in the nineteenth century; agnostic Aesthetic is Francesco Patrizio at the Renaissance, Kant in the eighteenth century; mystic Aesthetic is called Neoplatonism at the end of the antique world, Romanticism at the beginning of the nineteenth century, and if it be adorned during the former period with the name of Plotinus, in the latter it will bear the name of Schelling or of Solger, And not only are those attitudes and mental tendencies common to all epochs, but they are also all found to some extent developed or indicated in every thinker, and even in every man. Thus it is somewhat difficult to classify philosophers of Aesthetic according to one or the other category, because each philosopher also enters more or less into some other, or into all the other categories. Nor can these five conceptions and points of view be looked upon as increasable to ten or twenty, or to as many as desired, or that I have placed them in a certain order, but that they could be capriciously placed in another order. If this were so, they would be altogether heterogeneous and disconnected among themselves, and the attempt to examine and criticize them would seem altogether desperate, as also would be that of comparing one with the other, or of stating a new one, which should dominate them all. It is precisely thus that ordinary sceptics look upon various and contrasting scientific views. They group them all in the same plane, and believing that they can increase them at will, conclude that one is as good as another, and that therefore every one is free to select that which he prefers from a bundle of falsehoods. The conceptions of which we speak are definite in number, and appear in a necessary order, which is either that here stated by me, or another which might be proposed, better than mine. This would be the necessary order, which I should have failed to realize effectively. They are connected one with the other, and in such a way that the view which follows includes in itself that which precedes it.