He allows other creatures the right to live, even to the point of eating no meat, but if they encroach on his own right, and endanger his own survival, then he will defend himself as resolutely as other men. Nor is the situation changed if these creatures are not animal but human. Pacifism is useful as a protest against human proneness to resort to violence, so he sympathizes with it in specific cases. But its usefulness ends when unscrupulous aggression seeks to triumph and needs the education of defeat.
-- Notebooks Category 11: The Negatives > Chapter 3: Their Presence in The World > # 434