Blasphemy--the denial or denigration of God--has a long history. Jesus was tried for blasphemy. Early Christians felt that the Jews in taking such action were themselves guilty of it. But it is not a story confined to the remote past. The publication in 2005 of 12 cartoons in a Danish newspaper linking the prophet Mohammed to terrorism sparked outrage in the global Islamic community. And that was not an instance of blasphemy intruding itself upon a Western society unused to such issues within Christianity. In many societies blasphemy remained an offence in law and the prosecution of artistic...