"Obsession is a pair of blinders, and Beaumont wore his tightly. He far overstated the role of gastric acid, ignoring the digestive contributions of pepsin and of pancreatic enzymes introduced in the small intestine. As is regularly evidenced by tens of thousands of gastric reflux sufferers--their acid production pharmaceutically curtailed--humans can get by with very little gastric acid. The acid's main duty, in fact, is to kill bacteria--a fact that never occurred to Beaumont. What, for all his decades of experimenting, did he teach us? That digestion is chemical, not mechanical--but European experimenters, using animals, had shown this to be true two centuries earlier. That protein is easier to digest than vegetable matter. That gastric juices don't require the "vital forces" of the body. Not, in short, all that much."