We have already seen that, according to his ideas, the union of poetry, painting, music, and action in the “art work of the future” could be effected only by some sacrifice on the part of each art. Wagner plainly saw, as we must see, that the special feature which must yield to the necessary modification was _form_, or, more strictly speaking, _formality_. It was not form in the abstract that must be sacrificed, but forms in the concrete,—forms which owed their preservation to tradition, and not to any intrinsic worth or imperative demand of art. To preserve the old-fashioned operatic forms would have been to continue the dominance of music in the drama; for the poet would still have been a mere librettist, bound to provide for the aria, the duet, and the finale. To introduce a distinctive kind of versification, such as the Alexandrine, or the Spencerian stanza, would have made poetry the controlling element. The first problem set before Wagner, then, was to find subjects which would admit of the utmost freedom and unconventionality of treatment. Already in the embryonic state of his theories, the myth had forced itself upon his mind as the necessary kind of subject; and in the final working out of those theories to their end, the myth stood the test, with this important corollary, that it must be a myth embodying one of the great elementary thoughts of mankind. Turn which way he would, he found support for his belief. Did the legendary beings of the Greek stage lack the humanity and the ethical conditions necessary for great tragedy? On the contrary, as Mr. Stedman has put it:— “The high gods of Æschylus and Sophocles for the most part sit above the thunder: but the human element pervades these dramas; the legendary demigods, heroes, _gentes_, that serve as the personages,—Hermes, Herakles, the houses of Theseus, Atreus, Jason,—all are types of human kind, repeating the Hebraic argument of transmitted tendency, virtue and crime, and the results of crime especially from generation to generation.”[16] And when Wagner turned from the Greek drama to the philosophy of his beloved Schopenhauer, he found the same convictions forced upon him again by his teacher’s art theory. This theory is propounded in Book III. of “The World as Will and Representation.” The writer begs leave to quote a summary of it which he has made in a study of “Tristan”:—