History and Historiography of Science

Primer: Galenic Theory

I am not a historian of medicine by any stretch of the imagination, which is why it was sort of fun(ny) when the students from my intro to the history of science course this past spring seemed to take more interest in the medicine-related topics than any other.  So, for today’s history lesson, we’re going to do a quick overview of Galenic medical theory, which dominated university-based medicine instruction prior to the rise of anatomy and physiology in the early modern period, and which remained influential in the medical community as well as in geography (particularly in what we would now call ethnography).  Below we have a mixing of Galenic theory and physiognomy.

For reference’s sake: Galen of Pergamum was a Greek physician who lived in the 2nd century AD, and was inheritor to a large body of medical theory, which he organized, commented upon, criticized, and extended.  When Classical medical theory was revived in European university medical education in the later Middle Ages, his ouevre was still considered authoritative.

Galenic theory revolved around the balances of the four “humors”: blood, phlegm, yellow bile, and black bile (don’t try to connect it too much to current understanding of bodily fluids).  These humors were associated with the four elements (air, water, fire, and earth, respectively) as well as the properties of dryness, wetness, heat, and cold (blood, for example, was wet and hot).  Remaining healthy was a matter of maintaining a proper humoral balance.  It was not, of course, understood that many diseases were invasive.

One important way of maintaining or restoring balance was by regulating the body’s natural flows, both what went in and came out of the body, as well as its internal flows, which were considered subject to blockages.  The term “physic” (used regularly through the 19th century) had a pharmaceutical connotation, but rather than address pharmaceuticals to particular diseases, more often physic was used for their effect on bodily flows—I’ll avoid graphic descriptions here.  Assigning a proper regimen of physic meant having a proper understanding of theory and its relationship to specific cases.  Fever, characterized as it is by a heightened body temperature and excess sweating, was considered related to an excess of blood.  Hence the popularity of blood-letting and leach-applying.  Medical prescriptions were designed to assist the body in restoring balance, rather than to combat specific maladies.  It’s worth pointing out that physic always had a spotty reputation, although scientific types were frequently fascinated by it (Robert Hooke’s self-medication is semi-legendary).

One of the more notable aspects of Galenic theory was its interconnection of humoral balance not just with bodily fluids and specific instances of disease, but with everyday diet, environmental factors, and personality.  The prescription of certain diets, certain amounts of exercise, exposure to fresh air, etc., were more than just extraneous advice: they were well incorporated into the theoretical understanding of medicine.  Different temperaments (melancholic, choleric, phlegmatic, and sanguine) were specifically associated with humors, and individuals were often considered to have biases toward certain temperaments that could affect medical diagnoses and prescriptions.  Likewise, people of different regions were considered prone to certain kinds of temperaments: a notion that had a lasting impact on ethnography long after Galenic theory had become medically disreputable: even the terminology was frequently retained.  Of course, we retain much of the vocabulary to this day: people are still melancholy; those who are easily angered are “hot blooded” or “bilious”, while the unemotionally calculating are “cold blooded”; in some cultural traditions, certain foods are still related to their effects on personality.

What threw Galenic theory into disrepute was the rise of an increasingly mechanistic understanding of bodily function.  Dissection became a major aspect of medical education beginning in the 1500s, and the body became increasingly thought of as a mechanical automaton as its functions became more thoroughly understood (cue obligatory citation of William Harvey’s argument in his 1628 work “Anatomical Exercises on the Motion of the Heart and Blood in Animals” that the blood circulates rather than dissipates as it moves through the body).

Nevertheless, new intellectual postures did not translate directly into new medical practice.  Disease continued to be regulated by controlling bodily flows with physic, and prescriptions still included dietary and environmental advice.  Of course, many physicians were not university-trained, so many therapeutic regimens rested more on tradition than on theoretical understanding.  Also, circa 1800, the gradual rise in the safety and reputability of surgery, and more sophisticated nosology (identification of disease) and diagnosis steadily changed attitudes toward disease and its treatments, but provided no systematic basis for new understanding.  Therapeutic practice was thus not drastically overhauled until a reasonably correct etiology (assignment of causes of disease) began to emerge in the latter half of the 1800s.

This is all History of Medicine 101 stuff, so I won’t point interested readers to any specific sources (my advice is to find a recent general history of medicine book that includes classical theory), and I feel I’d better keep it to the basics lest I descend into error, if I haven’t already.  Still, I always get a kick out of the topic, because in some respects it is a very intuitive system, and thus it makes it easy to understand living in prior eras not in terms of error or ignorance, but in terms of what one genuinely felt was an appropriate and useful view of how the world works.