Richard Wagner (1813-1883)

(Wilhelm) Richard Wagner German romantic composer noted chiefly for his inventio of the music drama. His cycle of four such dramas The Ring of the Nubelung was produced at his own theatre in Bayreuth in 1876. His other operas include Tanhäuser (1845 revised 1861), Tristan and Isolde (1865), and Parsifal (1882).
This teaching [of the sinfulness of murdering and living upon our fellow beings] was the result of a deep metaphysical recognition of a truth; and, if the Brahman has brought to us the consciousness of the most manifold phenomenon of the living world, with it is awakened the consciousness that the sacrifice of one of our near kin is, in a manner, the slaughter of one of ourselves; that the non-human animal is separated from man only by the degree of mental endowment, that it has the faculties of pleasure and pain, has the same desire for life as the most reason-endowed portion of mankind. - Art and Religion
Human dignity begins to assert itself only at a point where man is distinguishable from the beast by pity for it. - The Regeneration of Mankind
The thought of their sufferings penetrates with horror and dismay into my soul, and in the sympathy evoked I recognise the strongest impulse of my moral being, and also the probable source of all my art. The total abolition of the horror we fight against must be our real aim. In order to attain this our opponents, the vivisectors, must be frightened, thotoughtly frightened, into seeing the people rise up against them with stocks and cudgels. Difficulties and costs must not discourage us . . . If experiments on animals were abandoned on grounds of compassion, mankind would have made a fundamental advance. - Letter to Ernst von Weber, 19 October 1879