So were all premodern doctors idiots who couldn't practice empiricism? Well, no - many of them are extremely intelligent, inquisitive people (people like Isaac Newton and Robert Boyle accepted bleeding as a treatment, so clearly "they weren't smart" or "they didn't understand the scientific method" isn't a good explanation). I think the answer is two pronged. One is simply that the placebo effect is extremely powerful, so even cures that we consider not to be efficacious in a clinical setting still "worked" in daily practice as placebos. The second is to look more closely at what someone with the scientific mind of Robert Boyle made of bleeding. He actually did do quasi-experimental trials involving blood loss and concluded that "excessive" bleeding was bad for human health. By the same token, he started doing chemical assays of various mineral and animal-based cures (like eating burnt lizards for epilepsy, and things like that) and began to lay the foundations for our later (18th/19th century) understanding of which minerals and vitamins are essential for human health. It's entirely possible that Greco-Roman doctors were doing similar things, but Boyle had the benefit of the ready dissemination of his findings via print and the world's first scientific journal (Philosophical Transactions), which happened to be edited by his close associate (Henry Oldenberg).
In short I think there was a kind of practical empiricism at work in the history of medicine that has always existed. But that it didn't begin to coalesce into clinical effective treatments until print culture made it possible for people to share their findings on a global level. This wasn't a simple march out of ignorance toward truth, though. And the reason for this is that the placebo effect of remedies like bleeding often "worked" just as well as the partially-effective treatments of premodern times, like, for instance, supplementing poor diets by eating the ashes of various animal and plant products.
If you have 15mins, watch his TED talk: http://www.ted.com/talks/david_deutsch_a_new_way_to_explain_....
http://en.wikipedia.org/wiki/Phlogiston_theory
Phlogiston theory is utterly wrong as an explanation for fire, but it "saves the appearances" (conforms to observable physical phenomena) quite well. I think Thomas Kuhn talks about it as an example of a mindset that required a paradigm shift to be thought about differently in Structure of Scientific Revolutions, which seems to be along similar lines as what I gather is Deutsch's Karl Popper-influenced take on scientific knowledge-making.
You also have to accept that even extremely intelligent people view evidence through the lens of their preconceptions. This can be a difficult thing to escape.
Meat in those days was regarded as an expensive luxury.
> He also won a gold medal in the Olympics for boxing so he was not just an ivory tower speculator.
If you are attempting to respond directly to my comment, then I don't see how being an athlete himself (even though that fact seems debatable) somehow means that his ideas aren't coloured in some way by his preconceptions. This has nothing to do with being in an 'ivory tower,' but instead to do with mapping the evidence to pre-conceived ideas and then calling it a day without questioning those idea themselves.
> Meat in those days was regarded as an expensive luxury.
It was an expensive luxury. I don't think that anyone is debating this. Even in China you can map the increase in consumption of meat to the rise of the Chinese middle-class in recent years.
I heard that's mostly a myth
edit:
there was apparently different Pythagoras, who was a boxer.
Similarly, I wouldn't be at all surprised if leeches and bleeding had some health giving effect. Perhaps it allows your body to make more appropriate white blood cells when you are sick.
BTW, can you recommend some good popular books on this subject? "Devils drugs and doctors" was one of my all time fave reads.
I wouldn't say that. Lamarck's theory wasn't pulled out of his ass; it fit the facts available to him, just like the phlogiston theory did. It happened to be wrong, but it wasn't because Lamarck was stupid.
Incidentally, leeches actually do have a place in modern medicine: after reconstructive surgery, they can be used to draw blood out of the affected area in a gentle, controlled fashion, reducing swelling and internal clotting and letting the several blood vessels heal much more reliably. This has nothing to do with the ancient use of leeches, though.
They may have had no insight into how or why this worked other than drinking ash tonics makes you feel better than not drinking them.
I know from my own experience that foods I hated as a kid turned out to be pretty bad for me - cauliflower, peanut butter, white bread, tomatoes - have real negative effects for one reason or another. On the other side, foods that I've craved at certain times like oranges or almonds, were counteracting a deficiency of one thing or another.
Of course, once this works once, the person who it worked for would spread the word for others with a similar problem.
[1] Poor choice of word, but can't think of a better one