To separate this primitive and all-powerful Dionysian element from tragedy, and to construct a new and purified form on the basis of an un-Dionysian art, morality, and conception of the world—this is the tendency of Euripides as it is now clearly revealed to us.
In this quote from Chapter Twelve, Nietzsche clearly elucidates the artistic goals of Euripides as he sees them, so that he may better attack them later. The crucial element of the Euripidean attack on tragedy is its denial of the Dionysian. Euripides strives to wrench art away from Dionysus's subversive grasp, so that he may purify art and align it with Socratic ethics. Euripides's conception of the world is a scientific one, and so allows no room for the mystical unity of Dionysus.
By attacking the Dionysian—which Nietzsche fervently believes to be the soul of tragedy—Euripides proves that he is the enemy of art. This argument is the subject of several chapters in the essay. However, while Nietzsche focuses great attention on Euripides's animosity towards Dionysus, he never provides concrete proof that such an animosity actually existed. We see here a clear example of Nietzsche's tendency to characterize his enemies as extreme, so that he can more easily uncover the absurdities inherent in such a position. As we have learned that Dionysus is the soul of art, anyone who is against Dionysus must also be against art. With this simple proof at hand, Nietzsche never needs to delve into a serious textual analysis that might put his argument at risk. For example, he fails to show conclusively how Euripides and Sophocles are radically more different from one another than Sophocles and Aeschylus, whom he groups in the same category of pre-Socratic tragedy.