"The Vietnamese have a secret weapon. It's their willingness to die beyond our willingness to kill. In effect, they've been saying, You can kill us, but you'll have to kill a lot of us; you may have to kill all of us. And, thank heaven, we are not yet ready to do that."
George Wald was an American biologist and physiologist known for research on visual pigments in the retina. He shared the 1967 Nobel Prize in Physiology or Medicine for discoveries concerning the primary physiological and chemical visual processes in the eye. He taught for decades at Harvard University.