In truth, dramatic characterization in music cannot be carried very far by the use of representative themes. Mozart, the greatest of all masters of this art, never dreamt of employing them; and, extensively as they are used in The Ring, they do not enable Wagner to dispense with the Mozartian method. Apart from the themes, Siegfried and Mimmy are still as sharply distinguished from one another by the character of their music as Don Giovanni from Leporello, Wotan from Gutrune as Sarastro from Papagena. It is true that the themes attached to the characters have the same musical appropriateness as the rest of the music: for example, neither the Valhalla nor the spear themes could, without the most ludicrous incongruity, be used for the forest bird or the unstable, delusive Loki; but for all that the musical characterization must be regarded as independent of the specific themes, since the entire elimination of the thematic system from the score would leave the characters as well distinguished musically as they are at present. One more illustration of the way in which the thematic system is worked. There are two themes connected with Loki. One is a rapid, sinuous, twisting, shifty semiquaver figure suggested by the unsubstantial, elusive logic-spinning of the clever one's braincraft. The other is the fire theme. In the first act of Siegfried, Mimmy makes his unavailing attempt to explain fear to Siegfried. With the horror fresh upon him of the sort of nightmare into which he has fallen after the departure of the Wanderer, and which has taken the form, at once fanciful and symbolic, of a delirious dread of light, he asks Siegfried whether he has never, whilst wandering in the forest, had his heart set hammering in frantic dread by the mysterious lights of the gloaming. To this, Siegfried, greatly astonished, replies that on such occasions his heart is altogether healthy and his sensations perfectly normal. Here Mimmy's question is accompanied by the tremulous sounding of the fire theme with its harmonies most oppressively disturbed and troubled; whereas with Siegfried's reply they become quite clear and straightforward, making the theme sound bold, brilliant, and serene. This is a typical instance of the way in which the themes are used.