Mockery of Muhammad, actual or perceived, has been at the heart of nearly all of these controversies over blasphemy.

This might seem unremarkable at first, but there is something curious about it, for the Prophet Muhammad is not the only sacred figure in Islam. The Quran praises other prophets — such as Abraham, Moses and Jesus — and even tells Muslims to “make no distinction” between these messengers of God. Yet for some reason, Islamist extremists seem to obsess only about the Prophet Muhammad.

Even more curiously, mockery of God — what one would expect to see as the most outrageous blasphemy — seems to have escaped their attention as well. Satirical magazines such as Charlie Hebdo have run cartoons ridiculing God (in the Jewish, Christian and Muslim contexts), but they were targeted with violence only when they ridiculed the Prophet Muhammad.