His plan was to unite all classes and parties in a conspiracy under one head, promising to each individual the things which he considered most desirable. For the Shi‘ites, it was to be a Shi‘ite conspiracy; for the Kharijites, it took a Kharijite tinge; for Persian nationalists, it was anti-Arab; for free-thinkers, it was frankly nihilistic. Abd Allah himself seems to have been a sceptic of the most refined stamp. The working of this plan was achieved by a system of grades like those in freemasonry. His emissaries went out, settled each in a village and gradually won the confidence of its inhabitants. A marked characteristic of the time was unrest and general hostility to the government. Thus, there was an excellent field for work. To the enormous majority of those involved in it the conspiracy was Shi‘ite only, and it has been regarded as such by many of its historians; but it is now tolerably plain how simply nihilistic were its ultimate principles. The first object of the missionary was to excite religious doubt in the mind of his subject, by pointing out curious difficulties and subtle questions in theology. At the same time he hinted that there were those who could answer these questions. If his subject proved tractable and desired to learn further, an oath of secrecy and absolute obedience and a fee were demanded—all quite after the modern fashion. Then he was led up through several grades, gradually shaking his faith in orthodox Islam and its teachers and bringing him to believe in the idea of an Imam, or guide in religious things, till the fourth grade was reached. There the theological system was developed, and Islam, for the first time, absolutely deserted. We have dealt already with the doctrine of the Hidden Imam and with the present-day creed of Persia, that the twelfth in descent from Ali is in hiding and will return when his time comes. But down the same line of descent seven Imams had been reckoned to a certain vanished Isma‘il, and this Isma‘il was adopted by Abd Allah ibn Maymun as his Imam and as titular head of his conspiracy. Hence, his followers are called Isma‘ilians and Seveners (_Sab‘iya_). The story which is told of the split between the Seveners and the Twelvers, which were to be, is characteristic of the whole movement and of the wider divergence of the Seveners from ordinary Islam and its laws. The sixth Imam was Ja‘far as-Sadiq (d. A.H. 148); he appointed his son Isma‘il as his successor. But Isma‘il was found drunk on one occasion, and his father in wrath passed the Imamship on to his brother, Musa al-Qazam, who is accordingly reckoned as seventh Imam by the Twelvers. One party, however, refused to recognize this transfer. Isma‘il’s drunkenness, they held, was a proof of his greater spirituality of mind; he did not follow the face-value (_zahr_) of the law, but its hidden meaning (_batn_). This is an example of a tendency, strong in Shi‘ism, to find a higher spiritual meaning