“I am not interested to know whether Vivisection produces results that are profitable to the human race or doesn't. To know that the results are profitable to the race would not remove my hostility to it. The pains which it inflicts upon unconsenting animals is the basis of my enmity towards it, and it is to me sufficient justification of the enmity without looking further.”- May 26, 1899
It's easy to forget the context that makes this so impressive: the same year he wrote the above quote (1899), Twain travelled to Budapest, Sweden, and the UK in search of various cures for his epileptic daughter Jean. Yet his moral opposition to animal testing never wavered.
What's more, five years later Twain wrote a short story about vivisection for his daughter Jean. Told in a dog's voice, it describes in first-person the sadness of a dog losing its pup to a medical experimenter. Entitled "Dog's Tale", it was published in Harper's Magazine. Check it out here.
Happy Birthday, Mr. Clemens!