SIMONE WEIL, the French philosopher and mystic, lived almost her whole life in wartime. As a child during the First World War, she gave up her pocket money to sponsor a soldier at the front. She fought in the Spanish Civil War. She spent the Second World War first in occupied France, and then with the Free French in London. She wrote and thought much about war. Now that war is once again raging in Europe, she has something to say to us on the subject. Like her favourite philosopher, Plato, Weil often expresses her thoughts through analogies. “Suppose we...