He showed the truth of his doctrine by concise, captious arguments. “As to the knowledge of God,” said he, “one of two courses must be followed: Claim to know God by the sole light of reason, or admit that one cannot know him by reason, but that men need instructors. Now he who rejects the first statement may not reject another man’s reason without admitting thereby the necessity of guidance.” Hassan combated in this way the claims of Greek sages. “The need of a guide being admitted we must know if every teacher is good, or if we must have infallible instruction. Now he who maintains that every teacher is good may not reject his opponent’s instructor without acknowledging the need of a teacher deserving the obedience and confidence of all men. It is shown,” added he, “that mankind has need of a true and infallible teacher. This teacher must be known so that men may accept his instruction with safety. He must have been designated and chosen; he must be installed; his truth must be proven. It would be folly to go on a journey without a skilled guide and director. This guide must be found before starting on the journey. “Variety of opinion is a real proof of error, accord in opinion shows truth, and unity is the sign of it. Diversity is a clear sign of error; unity comes from teaching obedience, diversity from freedom of thought; unity indicates submission to an Imam, freedom of thought goes with schism, and many leaders.” Apparently austere in his morals and respecting the Koran, Hassan Sabah forced all his subjects to live just as he did. The sternness of his methods may be known from these examples. He had one son clubbed to death for mere suspicion of being connected with the slaying of the Kuhistan governor without orders; the other for wine drinking and dissolute conduct. In the execution of his elder son he gave to his subjects an example of the penalty paid for interfering with the prerogative of the Grand Prior. The execution of the younger showed them the result of disobedience to principles—the principles ruling at Alamut. Just before his death in 1124 Hassan Sabah made his old comrade Kia Busurgomid his successor. Under this second chief murder increased very greatly; not merely enemies of the sect fell now by the dagger, but any prince or man who had an enemy could hire one of the Order to murder him. Rather than expose themselves to death, sovereigns and men of authority lived in apparent accord with the Assassins and obtained from the chief as a price of good-will a number of his devotees as aids in carrying out their own evil schemes for aggrandizement. Those men slew all pointed out to them, frequently, however, whole populations were punished for these crimes of their co-religionists. Kia Busurgomid was a man of great activity who followed the methods of Hassan, destroying the most illustrious leaders of the enemy.