Finally, it may be well to give some account of the constitutional question as it exists at the present day. The greatest of the Sultans of Islam is undoubtedly the Emperor of India. Under his rule are far more Muslims than fall to any other. But the theory of the Muslim State never contemplated the possibility of Muslims living under the rule of an unbeliever. For them, the world is divided into two parts, the one is _Dar al-Islam_, abode of Islam; and the other is _Dar al-harb_, abode of war. In the end, _Dar al-harb_ must disappear into _Dar al-Islam_ and the whole world be Muslim. These names indicate with sufficient clearness what the Muslim attitude is toward non-Muslims. It is still a moot point among canon lawyers, however, whether _Jihad_, or holy war, may be made, unprovoked, upon any _Dar al-harb_. One thing is certain, there must be a reasonable prospect of success to justify any such movement; the lives of Muslims must not be thrown away. Further, the necessity of the case—in India, especially—has brought up the doctrine that any country in which the peculiar usages of Islam are protected and its injunctions—even some of them—followed, must be regarded as _Dar al-Islam_ and that _Jihad_ within its borders is forbidden. We may doubt, however, if this doctrine would hold back the Indian Muslims to any extent if a good opportunity for a _Jihad_ really presented itself. The Shi‘ites, it may be remarked, cannot enter upon a _Jihad_ at all until the Hidden Imam returns and leads their armies. [Sidenote: THEORIES OF THE KHALIFATE]