This is the "religious people are crazy" doctrine. It proposes that all spiritual feelings are a product of sensationalism and self-fulfilling prophecy. This was the argument used by Festus against Paul, Festus said with a loud voice, Paul, thou art beside thyself; much learning doth make thee mad (Acts 26:24). The irony of the argument is that those who have no experience with the things of the Spirit are convinced that they are expert enough to pass judgment on the spiritually-minded. They assume that their lack of experience in spiritual matters is universal. Anyone teaching otherwise, they argue, is just delusional. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned (1 Cor 2:14).
"Now many of my friends think like this, that Mormons must be deranged. We have a professor from Hebrew University who is here (at BYU) now. He thinks that anybody must be crazy who can believe in an angel. That's just impossible; there's something wrong there. He just can't get it through his head, although there it is. That's why he is so interested in being here with people who actually believe it. 'But behold, it is the effect of a frenzied mind'" (Teachings of the Book of Mormon, lecture 54, p. 423)