> I recently read The Secrets of Alchemy by Lawrence Principe, which I loved, especially because he tries to replicate ancient alchemical recipes in his own lab. And sometimes he succeeds! For instance, he attempts to make the “sulfur of antimony” by following the instructions in The Triumphal Chariot of Antimony (Der Triumph-Wagen Antimonii), written by an alchemist named Basil Valentine sometime around the year 1600. At first, all Principe gets is a “dirty gray lump”. Then he realizes the recipe calls for “Hungarian antimony,” so instead of using pure lab-grade antimony, he literally orders some raw Eastern European ore, and suddenly the reaction works! It turns out the Hungarian dirt is special because it contains a bit of silicon dioxide, something Basil Valentine couldn’t have known.

> No wonder alchemists thought they were dealing with mysterious forces beyond the realm of human understanding. To them, that’s exactly what they were doing! If you don’t realize that your ore is lacking silicon dioxide—because you don’t even have the concept of silicon dioxide—then a reaction that worked one time might not work a second time, you’ll have no idea why that happened, and you’ll go nuts looking for explanations. Maybe Venus was in the wrong position? Maybe I didn’t approach my work with a pure enough heart? Or maybe my antimony was poisoned by a demon!

> An alchemist working in the year 1600 would have been justified in thinking that the physical world was too hopelessly complex to ever be understood—random, even. One day you get the sulfur of antimony, the next day you get a dirty gray lump, nobody knows why, and nobody will ever know why. And yet everything they did turned out to be governed by laws—laws that were discovered by humans, laws that are now taught in high school chemistry. Things seem random until you understand ‘em.

Well, this example doesn't just fail to support the argument, but undercuts it. Basil successfully identified the kind of antimony that would work, -despite- having no concept of sulfur dioxide. He did not write down something like "not all kinds of antimony work for this recipe, so get a bunch of different kinds and try them all" -- that, or a stronger version ("sometimes the recipe fails, we don't know why"), would support the author's point.

So we're left with the author trying to argue that this alchemist thought the world was "too hopelessly complex to ever be understood" on the basis of ... the alchemist correctly identifying the ingredient that would make the recipe work.