This comment examines the tension between freedom of expression and freedom of religion by embedding the Charlie Hebdo cartoons in a wider, century-old European tradition of publications mocking religion, including Christianity. It describes, and draws lessons from, the 19th century blasphemy case against the British Freethinker newspaper, whose "technique of offense" was similar to that of Charlie Hebdo. Finally, the comment tackles the problem of violent response to text or images that mock religion, pointing out that malicious intermediaries often carry such messages between social groups or across national borders-greatly escalating the risk of violence. This comment examines the tension between freedom of expression and freedom of religion by embedding the Charlie Hebdo cartoons in a wider, century-old European tradition of publications mocking religion, including Christianity. It describes, and draws lessons from, the 19th century blasphemy case against the British Freethinker newspaper, whose "technique of offense" was similar to that of Charlie Hebdo. Finally, the comment tackles the problem of violent response to text or images that mock religion, pointing out that malicious intermediaries often carry such messages between social groups or across national borders-greatly escalating the risk of violence.