22 I do not accept the devil's testimony but his confession. The devil spoke unwillingly, being compelled and tormented. That which wickedness suppresses, torture extracts. The devil yields to blows, and the Arians have not yet learned to yield. How great have been their sufferings, and yet, like Pharaoh, they are hardened by their calamities! The devil said, as we find it written: “I know You Who You are, You are the Son of the living God.” And the Jews said: “We know not whence He is.” The evil spirits said today, yesterday, and during the night, We know that you are martyrs. And the Arians say, We know not, we will not understand, we will not believe. The evil spirits say to the martyrs, You have come to destroy us. The Arians say, The torments of the devils are not real but fictitious and made-up tales. I have heard of many things being made up, but no one has ever been able to feign that he was an evil spirit. What is the meaning of the torment we see in those on whom hands are laid? What room is there here for fraud? What suspicion of pretence?
Source: Letters (New Advent)