There was also a false mystic potency. It emanated from spirits who were conceived of as alien and hostile, and, while it was not strong as the true “virtue,” natural phenomena yielded before it and it had its own miracles, which however were always deceitful and malignant in purpose. This “virtue” is associated with the devil, demons, soothsayers, magicians, pagans and pagan gods, and heretics, and through them is continually engaged in aggressive warfare on the true “virtue.”[21] For the attainment of the true mystic potency asceticism was the method. This was not a withdrawal from lower activities of life to gain more power for higher activities, but it was undertaken in contempt of life, and in the more thoroughgoing cases the only restraint was the desire to avoid self-destruction, which was forbidden. Almost every known method of self-denial and self-mortification was practised. Humility of mind was insisted on as an always necessary element. Fasting was part of the prescribed method. The strength of the motive behind asceticism may be judged from the practice of immuring,[22] several specimens of which are related by Gregory. In this the ascetic was shut in a cell and the door walled up and only a narrow opening left to hand in a scanty supply of food. Here he was to remain until he died. Such men were regarded as having the true “virtue” in the highest degree. In reality their life must have made them distinctly inferior in all the ordinary virtues of a natural existence.[23] As asceticism was the method by which mystic potency was attained, so miracles were the product, and the proof that it had been acquired. Of course in theory the main object of the mystic was to assimilate himself to the supernatural and not expressly to work miracles. Still to society in general the miracles were the important thing. In the first place they served the immediate purpose for which a miracle might be needed, healing the sick or driving out a demon or something of the sort; in the second place they encouraged society by evidencing the fact that things in general were right and that their spiritual leaders had the right “medicine.” Incredulity is not to be expected in such a situation. The miracle played an integral part in the life-theory of the time. It was the proof of religion and it did not need to be proved itself. Furthermore many miracles were real; for example, the cessation of a pain or natural recovery from a sickness would be regarded as a miracle.