The killing of the horses [a bullfight in Madrid, he visited in June 1910] by the bull is very horrible, much more so as they have no chance to escape and are ridden up to the bull to be butchered.... the entry of the bull into the ring however is very beautiful; his surprise and the first charges he makes are very pretty.

In a letter to his sister, June 9, 1910; as quoted in "Edward Hopper", Gail Levin, Bonfini Press, Switzerland 1984, p. 23 - 1905 – 1910 (Travel)