IMO, we already have the mental-disease equivalent of germ theory, it’s just far more complex and not yet well-understood by enough people to have broad social impact.
“The germ theory was proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. Such views were held in disdain, however, and Galen's miasma theory remained dominant among scientists and doctors.” - https://en.m.wikipedia.org/wiki/Germ_theory_of_disease
> Marcus Terentius Varro was called the most learned of the Romans. But what did he know, and how did he know it? I ask because of this quote, from Rerum rusticarum libri III (Agricultural Topics in Three Books):
> Precautions must also be taken in the neighbourhood of swamps, both for the reasons given, and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases.
> I get the distinct impression that someone (probably someone other than Varro) came up with an approximation of germ theory 1500 years before Girolamo Fracastoro. But his work was lost.
The ancient Greeks were long ago discussing the possible existence of “animalcules.” Fracastaro gets credit because he wasn’t just philosophizing, he described actual disease in great detail with supporting cases (I hesitate to say “data,” that wasn’t really a thing yet) to argue for its mechanism.
It’s the difference between a stoner strumming his guitar, “dude, what if we’re all, like, strings?” and string theory.
I think the advice "don't live near a swamp, because the tiny invisible creatures in there will make you sick, and if you do have a farm next to a swamp, sell it" is a little more detailed than "dude, what if we're all, like, strings?"
Describing disease in great detail is nothing the Romans didn't also do, nor does it have anything to do with the germ theory of disease.
That advice applies equally well to miasma (and, in fact, it’s ability to accurately relate to geography of disease is part of why it was taken seriously.) Which is why F. gets credit for actually making detailed observations and hypotheses that we’re borne out.
No, the advice that tiny creatures within the swamp will make you sick does not apply to miasma; those are competing theories.
The advice "stay away from swamps; they'll make you sick" does indeed apply to both theories.
Detailed observations also apply to both theories. Everyone everywhere has detailed observations of disease, usually the same ones.
Girolamo Fracastoro did not, as far as I can see, make any hypotheses or predictions that other people hadn't made thousands of years before he was born, nor did he observe in any greater or more relevant detail. He exemplifies the observation "Christopher Columbus is famous for being the last person to discover America". He made what had been common knowledge common knowledge again.
Unless you can identify something he did that was notable? What hypothesis did he make that Varro didn't already know? I ask because "tiny creatures get into your body and cause disease" is pretty much the beginning and end of modern germ theory today.
It isn't even scientifically accurate to believe that mental illness is caused exclusively by brain malfunctions. Other bodily systems, especially the gut, also seem involved - never mind the mysterious role of genetics, and the slightly less mysterious but hard to pin down influence of environmental and social stresses.
“The germ theory was proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. Such views were held in disdain, however, and Galen's miasma theory remained dominant among scientists and doctors.” - https://en.m.wikipedia.org/wiki/Germ_theory_of_disease