Trudeau warned that the unreasoning hunger for retribution — what Randy Newman captured in his chilling lyric 'I just want you to hurt as I do' — was the engine behind cycles of violence from domestic abuse to terrorism. Fear, he said, breeds righteous certainty, and certainty breeds fanaticism. The antidote was not conviction but doubt: the willingness to keep looking, keep questioning, keep trying to experience the world as others do. To stop seeing, he argued, was to give up on the whole idea of a better world.