There is a third Aesthetic, the _intellectualist_, which, while also recognizing the reducibility of aesthetic facts to philosophical treatment, explains them as particular cases of logical thought, identifying beauty with intellectual truth; art, now with the natural sciences, now with philosophy. For this Aesthetic, what is prized in art is what is learned from it. The only distinction that it admits between art and science, or art and philosophy, is at the most that of more or less, or of perfection and imperfection. According to this Aesthetic, art would be the whole mass of easy and popular truths; or it would be a transitory form of science, a semi-science and a semi-philosophy, preparatory to the superior and perfect form of science and of philosophy. A fourth Aesthetic there is, which may be called _agnostic_. It springs from the criticism of the positions just now indicated, and being guided by a powerful consciousness of the truth, rejects them all, because it finds them too evidently false, and because it is too loth to admit that art is a simple fact of pleasure or pain, an exercise of virtue, or a fragmentary sketch of science and philosophy. And while rejecting them, it discovers, at the same time, that art is not now this and now that of those things, or of other things, indefinitely, but that it has its own principle and origin. However, it is not able to say what this principle may be, and believes that it is impossible to do so. This Aesthetic knows that art cannot be resolved into an empirical concept; knows that pleasure and pain are united with the aesthetic activity only in an indirect manner; that morality has nothing to do with art; that it is impossible to rationalize art, as is the case with science and philosophy, and to prove it beautiful or ugly with the aid of reason. Here this Aesthetic is content to stop, satisfied with a knowledge consisting entirely of negative terms. Finally, there is an Aesthetic which I have elsewhere proposed to call _mystic_. This Aesthetic avails itself of those negative terms, to define art as a spiritual form without a practical character, because it is theoretic, and without a logical or intellective form, because it is a theoretic form, differing alike from those of science and of philosophy, and superior to both. According to this view, art would be the highest pinnacle of knowledge, whence what is seen from other points seems narrow and partial; art would alone reveal the whole horizon or all the abysses of Reality.