The Ismailian apostles trained in the House of Science in Cairo, which had been founded and developed in the Fatimid interest, taught their secret doctrines to a few chosen followers. These doctrines were communicated slowly and with many precautions. The chiefs or apostles at Cairo, the prime masters of all sacred wisdom, initiated disciples. There were nine degrees through which those of the faithful had to pass to receive the great mystery. But before giving the first degree to any novice whatever the Master took from him an oath devoting the applicant to the greatest calamities of this life, and the keenest sufferings of the next, if he kept not strict silence touching that which was revealed to him, or if he ceased to be the friend of all friends of the Ismailians, and the enemy of all their enemies. When the oath was accepted the Master took a fee for that which he was going to communicate, and he never advanced any novice from degree to degree, till he saw that the man had assimilated to the utmost everything taught him. The first step in instruction was that God has at all times given the task of establishing His worship, and preserving it, to Imams, his chosen ones, who are the sole guides of the faithful. As God has created the most beautiful of all things and the noblest, by sevens, such as the heavens and the planets, he has fixed the number of Imams at seven, namely: Aly, Hassan, Hussein, Ali Zayn al Abidin, Mohammed Bakir, Jaffar es Sadik, and Ismail, or Mohammed, the son of Ismail, who surpasses all other Imams in occult wisdom and in knowledge of the mystic sense of things visible. He explains these mysteries to those of the initiated who inquire, for he has been instructed by God himself, and he communicates his marvelous gifts to the Dayis, or Ismailian apostles, to the exclusion of all other sectaries of Ali. Like the Imams, the word-endowed prophets sent to establish new religions were seven in number. Each prophet had one vicar (siwes) as aid who upheld true religion after the death of his principal, and six other vicars, who appeared after him among men. In distinction to the word-endowed prophets the vicars were called “the dumb,” because they merely walked in the way which had been traced for them previously. When these seven vicars pass from the earth, a new prophet comes who sets aside the preceding religion and is followed by seven mute vicars. These changes follow one another till the coming of the seventh word-endowed prophet, who is the lord of the present, that is, lord of the age in which he is manifest.