Aristotle assigns to music — and implicitly also to the other arts — four functions. These are (1) that of serving as an amusement; (2) that of moral education; (3) that of constitut ing an enjoyable exercise; (4) that of °purifi cation.' The first and the third of these four values are obviously only the passive and the active phases of a single one. As for the em phasis which Aristotle puts on the moral pur pose in art, it is to be remembered that beauty and morality are for him essentially one and the same thing, so that this moral purpose un doubtedly stands not only for what we should ordinarily know by that name, but also for the intrinsic beauty of the work. The 'Ipurifica tion" which art is supposed to produce is an emotional one. If we accept Zeller's interpre tation of this point, Aristotle means that music and the tragedy furnish a safe outlet for our more violent emotions by turning them from the individual and particular to the general and universal, owing precisely to that typical reference which we have seen to be character istic of art in the Aristotelian system.
The next great figure in esthetics is the Neo-Platonist Plotinus (q.v., 2(k-269 A.D.). Like all the Greek philosophers, in fact, he too maintains that the beautiful is intimately re lated to the good, but this relationship receives less emphasis in his system than in those of Plato and Aristotle. Plotinus is a mystic, and he considers that all things are emanations from the One, which he also knows as the Good. In so far as these emanations are per ceptible to our external senses, we experience them as beauty. As Bosanquet interprets this view, it means that all that symbolizes in sensu ous form laws eternally active ranks as beau tiful. This symbolization need not involve any symmetry or order or proportion in the sym bol—indeed the One itself has no parts, and can consequently share in none of these quali ties. Whereas on the Aristotelian view only that which possesses structure can be beautiful, Plotinus holds that nothing can partake of beauty whose parts are not beautiful in them selves.
Plotinus is the last of the ancient thinkers to have added anything really new to the theory of esthetics. With the rise of Chris tianity and the barbarian incursions from the north and east, art and the theories of art to which it gives rise enter on a period of retro gression. Save as a tool of religion art is dormant until the wonderful centuries that foretoken the Renaissance. As a consequence, although we do find treatments of esthetic problems from the time of St. Augustine to that of St. Thomas, these have been singularly arid and without fruit in modern esthetic theory. It is remarkable, however, that the Renaissance itself, fertile in artistic interest and artistic production as perhaps no other time has been, should have left so small a con tribution to the esthetics of to-day, and that it is to the pedantic,. dry Enlightenment that we must look for the rebirth of the theory of beauty and art.
As in all the philosophical theories of the Enlightenment, we find a sharp contrast be tween the empiricistic, Baconian, "tough minded" tendency of the British speculators and the "tender-minded" rationalism of the Continent. The Continental tradition in es
thetics begins with Baumgarten (1714-62), a follower of Leibniz (q.v., 1645-1716). Leibniz believed that our experience of what is appar ently matter is really the result of a confused perception of an aggregate of entities he calls monads, which are essentially spiritual or mental in nature. Accordingly Baumgarten considers that the property of these monads which is known to our intellect as the perfection of the ideas which they possess and the consequent correctness or truth of these is perceived after the confused method of our senses as beauty. It will be seen that this view of Baum garten belongs to that utter pedantry which characterizes the decadence of the Leibnizian tradition, yet it is the first sign of the renas cence of a philosophical esthetics.
Not many years after Baumgarten we find the question of the norms and branches of art treated by Winckelmann and by Lessing (q.v., 1729-81). Winckelmann's interest is primarily in those arts that appeal to the sense of vision, while Lessing, on the other hand, approaches esthetics from the standpoint of the poet. Winckelmann has a formal view of the nature of beauty not unlike that maintained by the British artist Hogarth, but he does not make beauty the sole end of artistic endeavor, for he finds that beauty and expressiveness are not perfectly compatible. Lessing follows Winckel mann in applying the word "art" primarily to the plastic arts, so that poetry is for him some thing quite outside the scope of art. Conse quently he is able to maintain that the ugly has its place in poetry, but not in art. Lessing fol lows Aristotle closely, even pedantically, in his views on the drama and on the relative func tions of the several arts.
In Britain at about this time Home (Lord Kaimes) (1696-1782) develops an esthetical theory on the lines laid down by Shaftesbury and Hutcheson. This view is verbally hedon istic, making the test of certain sense of immediate satisfaction, yet in essence it is not hedonistic at all, for this satisfaction is said to be not only quantitatively but qualitatively distinct from the satisfaction of the useful or the merely agreeable. This view in effect amounts to the postulation of a peculiar ms thetic feeling. Like the Greeks, the members of this school of British thought maintain that the norms of ethics and aesthetics are closely related, but it is the ethical norm which they subordinate to the aesthetic one, for they find the basis of morality in the beauty of good deeds. Edmund Burke develops this empiri cistic vein in aesthetics further, and derives the feeling for the sublime from the instinct for self-preservation, that for the beautiful from the social impulse. The technical side of artis tic theory is investigated by Hogarth (q.v.), who places great emphasis on the beauty of form or design.