About the Demon of Socrates Cardan has much to say in the _De Varietate_. He never even hints a doubt as to the veracity and sincerity of Socrates. He is quite sure that Socrates was fully persuaded of the reality of his attendant genius, and favours the view that this belief may have been well founded. He takes an agnostic position,[234] confining his positive statement to an assertion of his own inability to realize the presence of any ghostly minister attendant upon himself. In the _De Subtilitate_ he tells an experience of his own by way of suggesting that some of the demons spoken of by the retailers of marvels might be figments of the brain. In 1550 Cardan was called in to see a certain woman who had long been troubled with an obscure disease of the bladder. Every known remedy was tried in vain, when one day a certain Josephus Niger,[235] a distinguished Greek scholar, went to see the patient. Niger, according to Cardan's account, was quite ignorant of medicine, but he was reputed to be a skilled master of magic arts. The woman had a son, a boy about ten years old, and Josephus having handed him a three-cornered crystal, which he had with him, bade the youth secretly to look into it, and then declare, in his mother's hearing, that he could see in the crystal three very terrible demons going on foot. Then, after Josephus had whispered certain other words in the boy's ear, the boy went on to say that he beheld another demon, vastly bigger than the first, riding on horseback and bearing in his hand a three-tined fork. This monster overthrew the other demons, and led them away captive, bound with chains to his saddlebow. After listening to these words the woman rapidly got well, and Cardan, in commenting on the event, declares that she must have been cured either by the agency of the demons or by the force of the imagination, inasmuch as it would be difficult, if not impossible, to invent any other reason of her recovery.[236] In another passage of the _De Subtilitate_ he displays judicious reserve in writing of Demons in general.[237]