We’ve all experienced the torment of an upset stomach and the horror of indigestion. But most people are probably not aware of just what a dastardly threat dyspepsia poses. If certain 19th century physicians are to be believed, tummy-ache has the power to undermine religions. Not only can it place one at the mercy of ghosts and apparitions, it can also cause the body to overwhelm the soul itself, putting one’s very immortality at risk. This may sound bizarre, but such claims were made by a number of people prominent in their respective fields and widely respected in intellectual circles.