Indeed. I'm a historian of medicine and sometimes think that premodern healers get a bad rap. Yes, some of the cures you find in medieval or early modern medicine are absurd (like "bleeding until syncope"). But once in awhile you run into something like this, from a 17th century Portuguese physician named Duarte Madeira Arraiz:

"They spread the sickness throughout the world, each army bringing it to its respective country... and it was related by Christopher Columbus of his discoveries in the Occidental Indies to the King of Spain, that in the lands he discovered he encountered many Indian men and women who suffered from the disease of the morbo gallico [syphilis], and so those among the soldiers and men of arms who had communication with the Indian women and with the 'mulheres publicas' of the land easily spread this contagion to the greater part of the Spanish army, and from thence, to the French."

He comes pretty close to anticipating germ theory here, arguing that syphilis was sexually transmitted and correctly theorizing that it had New World origins and was spread by European colonization. These people weren't dumb.

Are you saying that syphilis was widespread among native Americans? Post aside, that is a fascinating fact.

Looks likely but not proven. https://en.wikipedia.org/wiki/Syphilis#History

It is interesting. It was terrible that early explorers carried diseases that killed millions in the regions they went to. Its reassuringly symmetric that diseases went the other way as well. I didn't know that 100k+ still die from it every year.

Yes, syphilis was first noticed when it started to spread around Europe in the 1490s not long after sustained contact with the Americas. So it's likely that it did come from the Americas, but it hasn't been proven.

It's also possible that it coincidentally originated in Europe around the same time and spread to the Americas. By the time people started looking into where it had come from, it was widespread in both places and the exact origins were obscure. Nobody appears to have recorded the prevalence of syphilis in the Americas during the early years of European contact.

Whether it was or wasn't, there's no real reason not to think that each population transmitted diseases to the other, who lacked natural or acquired immunity.

Yeah, it's kind of funny how we arrived at some of the right answers for totally the wrong reasons. The whole "bad air" concept? Total hokum, but an abundance of fresh air will help control airborne transmission.

If you realize that experiment generally orecedes theory, it's completely sensible. Experiments are reproducible, theories are abstract. Making could decisions is more useful than having correct explanations.

> Experiments are reproducible

Not nitpicking (at least that's not my intent), just adding: Only if you know what the variables are.

This occurred to me because I'm myself an interesting medical case beating even a professor of medicine's prediction, as well as independent ones from various doctors about other things that turned out to be symptoms of the same underlying chronic poisoning issue that I had to diagnose myself, and only then find the right specialist for it. There has been sooo much interesting stuff going on in my body during years of slow recovery (and a few "miracles" that left doctors literally speechless), but I would not be able to say how you could repeat the "experiment". Too little is known about any of what goes on inside me right now, my doctor (researcher at university clinic) has long ago admitted that we left the area of known study-supported medicine behind.

I suspect a few mechanisms based on observing myself that I have no way and no idea how to prove. So I'm of course not certain what I can claim, or what exactly happened, but neither would I know how to repeat my personal experiment even if human experiments were possible. It's just too much unknown territory. And in the end my experiences will all be lost, unfortunately.

An example for something I suspect: Some diseases like the common cold may not always be orthogonal and superfluous. In my case, over the years, I got more and more the impression that it actively helped my body to get rid of what was stored over decades. I suspect that everything is much more intertwined and connected and not separate. One prediction I could make based on this suspicion is that if we were to be able to eliminate mild diseases like the cold completely we would get more serious diseases or other issues down the road. That's not a practical experiment though, maybe some large-scale observational studies can get some hints one way or the other, but it will be too messy and too uncertain for anything even close to a definite proof or disproof.

Another thing I suspect is that even very low level exposure (far below officially allowed levels) to heavy metals has very real consequences - it's just that on an individual basis we are almost utterly unable to show it. We can do it only on a population basis, and we all know how messy that is with all the known and unknown confounders.

Many knowledge starts with noticing correlation.

Then disproving causation. A fascinating use of Mammoth Cave in its history was a "good air" study on tuberculosis patients, because caves have great, naturally tempered air. That airflow is also tightly enclosed and many tourists and the doctors themselves caught the disease. It was a terrible way to help prove germ theory, but at the same time its hard not to blame them for trying because it was such a serious disease and anything to help was more than they had.

You could argue that the entire human body along with every infections disease got invented in the same way.