We can destroy animals more easily than they can destroy us; that is the only solid basis of our claim to superiority. We value art and science and literature, because these are things in which we excel. But whales might value spouting, and donkeys might maintain that a good bray is more exquisite than the music of Bach. We cannot prove them wrong except by the exercise of arbitrary power. All ethical systems, in the last analysis, depend upon weapons of war.”

— Bertrand Russell, If Animals Could Talk (14 September 1932)