_Siegfried_, _Götterdämmerung_, _Tristan und Isolde_ are exact repetitions of the essential content of the _Walküre_. It is always the dramatic embodiment of the same obsession of the terrors of love. Siegfried sees Brunhilde in the midst of her fire-circle, and both instantly fall into each other’s arms in a rage of love; but Siegfried must expiate his happiness with his life, and falls under the steel of Hagen. The mere death of Siegfried does not suffice for Wagner’s imagination as the inevitable consequence of love; destiny must show itself more terribly. The castle of Asgard itself breaks out in flames, and the slave of love in dying drags to his own perdition all the gods of heaven along with him. _Tristan und Isolde_ is the echo of this tragedy of passion. Here also is the complete annihilation of the sentiment of duty and self-conquest, by the springing up of love both in Tristan and Isolde; and here also is death as the natural end towards which love is hurried. To express his fundamental mystic thought, that love is an awful fatality wherewith the unapproachable powers of destiny visit the poor mortal incapable of resistance, he has resort to a childishly clumsy device; he introduces into his compositions love-philtres of potent spell, now to explain the birth of the passion itself, and to indicate its superhuman nature, as in _Tristan und Isolde_; now to withdraw all the moral life of the hero from the control of his will, and show him as the plaything of super-terrestrial forces, as in the _Götterdämmerung_.