And this familiar problem is further complicated—even more than in the Christian case—by the matter of succession. Unlike Jesus, who apparently undertook to return to earth very soon and who (pace the absurd Dan Brown) left no known descendants, Muhammad was a general and a politician and—though unlike Alexander of Macedonia a prolific father—left no instruction as to who was to take up his mantle. Quarrels over the leadership began almost as soon as he died, and so Islam had its first major schism—between the Sunni and the Shia—before it had even established itself as a system.
