How to be healthy with Galen

Part XXIV of the Ancient Wisdom for Modern Readers series

[Based on How to Be Healthy: An Ancient Guide to Wellness, by Galen, translated by Katherine D. Van Schaik. Full book series here.]

I’ve made it a personal project for a while now to read, and comment on, all of the entries in the ongoing “Ancient Wisdom for Modern Readers” series being put out by Princeton University Press. Besides, the editor of the series, Rob Tempio, has promised me a nice lunch out if I keep going, so…

The question can reasonably be raised, though, as to why anyone would think that ancient wisdom should, in fact, be of any use to modern readers. After all, we are talking about people who wrote stuff down two or more millennia ago, and we’ve learned a thing or two in the meantime. I have addressed this issue in a previous essay, but the current entry in this series is a particularly good test case.

We are talking about Galen of Pergamon, the personal physician of the emperor Marcus Aurelius, and arguably the best trained doctor in the entire Mediterranean world of the second century. Translator Katherine Van Schaik has carefully selected excerpts of works by Galen that are still relevant today, and she acknowledges that this was no trivial task, since medicine has made giant leaps forward in the course of the past two millennia (well, mostly in the past couple of centuries or less).

She found Galenian advice that a modern physician would endorse concerning five subject areas: the connection between mind and body, the value of exercise, the notion of individualized medicine, the importance of sound nutrition, and the very definition of health and disease.

It is telling, though, that these excerpts represent a fraction of what Galen wrote, and he was a very prolific writer. Scholars estimate that a whopping ten percent of all extant Greek literature written before 350 CE is from Galen, and we know that not everything he wrote survived!

The reason Van Schaik had to be so wisely picky in her selections is that many of the notions Galen subscribed to are, of course, no longer scientifically valid, and it would be stunning if that were not the case. For instance, Galen thought that the heart took in “nutritious” venous blood from its right side and combined it with air (pneuma). This is not the case, as any modern introductory text of human anatomy and physiology will confirm.

Then again, Galen understood the importance of three distinct organ systems in the human body: the brain, the heart, and the liver. Moreover, he chastised the Stoics for believing that the seat of the (material) soul was the heart. It is, obviously, the brain (if by “soul” we mind mind).

Statue of Galen in Pergamon, the city where he was born. Photo by the Author.

But the reason to read Galen today is not because of the accuracy of his science. Other than the obvious historical value of appreciating what one of the brightest minds of antiquity was thinking and why, there is the philosophical aspect, the real incentive for us to care about ancient thought. Note, in fact, that the Princeton Press series is entitled “Ancient Wisdom for Modern Readers,” not ancient knowledge. It is that crucial difference that all too often gets lost in modern scientistic discussions of what is or is not valuable. We have most certainly accumulated a lot of knowledge since the Greco-Romans. But not nearly as much wisdom, unfortunately.

For instance, one of the characteristics that distinguished Galen’s thought is that he was skeptical, but not too much. His father, Nikon, who was an architect, personally taught his son until the age of 14, when he was judged old enough to attend lectures by professional philosophers. Nikon, however, personally interviewed each candidate to the role of tutor of his son and advised Galen to sample widely but not to commit wholeheartedly to the teachings of any particular school. Which did not mean that Galen would not endorse one theory or another, or even develop his own; but it meant that he did so while being keenly aware that he, or anyone else, could be wrong.

Galen’s father was knowledgable in architecture, astronomy, geometry, and mathematics, and taught his son the importance of sharp and precise thinking. That sharpness and precision came handy to Galen throughout his career, as two case studies will readily demonstrate.

In 157 CE, in his home city of Pergamon, Galen served as physician for the local professional gladiators, a difficult job to say the least. He got the job by challenging the other candidates to a fit of impromptu medical bravura: he cut open the abdomen of a monkey and asked if anyone were able to reposition the entrails correctly and close the wound. Nobody moved, at which point he skillfully performed the deed himself. During his first year on the job, Van Schaik tells us, only two gladiators died under his watch, and none during the following four years.

But Galen’s skills were not impressive only in the obviously all-important practical aspect of medicine. He was also interested in theory and especially epistemology, that is understanding why certain schools employed some methods rather than others. At that time there were, broadly speaking, three approaches to medicine: the Dogmatists, or Rationalists, who were committed to study the “hidden causes” of diseases; the Empiricists, who preferred to rely on empeiria, that is, direct experience; and the Methodists, who, like the Empiricists, rejected theorizing and divided diseases into three categories (excessive looseness, excessive constriction, and a mix of the two).

Galen was a major critic of the Methodists, but was also aware that both the Dogmatists and the Empiricists had a point. Medicine is eminently practical and experiential, just as the Empiricists claimed. But it wouldn’t make much progress if it didn’t also investigate the causes of diseases, as the Rationalists insisted. It is precisely this sort of mixed epistemology that has made possible the flourishing of modern medical science.

The spectacular theater at Pergamon, home of Galen. Photo by the Author.

Let’s take a closer look at the text by way of a few highlights, accompanied by brief commentaries:

“From the very first, I made this distinction, that an error occurs in accordance with false belief, and that affection occurs according to some irrational faculty in us that does not comply with reason; colloquially, both in a more general sense are called errors.” (Affections and Errors of the Soul)

Here Galen sounds eminently Stoic, and sure enough in what follows he goes on to mention Chrysippus of Soli, the preeminent Stoic logician. The word that Van Schaik has translated “affection” is pathos, the term with which the Stoics labeled unhealthy emotions like anger.

We make mistakes, Galen is saying, because our thinking goes astray and we endorse false beliefs. These beliefs affect our emotions, which means that we don’t just make intellectual errors, but emotional ones as well. We live in a world where it is increasingly unacceptable to even question people’s emotional responses, as if they were unavoidable and not the result of incorrect judgments. We would do well to revise our position on this matter.

“How great a good physical exercise is for health, and how it ought to take precedence over food, was adequately stated by men of earlier generations, the best philosophers as well as doctors. But how much greater the exercise with the small ball is than other exercises no one of those before has ever sufficiently expounded.” (On Exercise with a Small Ball)

Galen wrote quite a bit about what he regarded as the perfect exercise, a game that uses a small ball. It’s unfortunate that historians don’t really seem to know what sort of ball game he was referring to! What is important, though, is that he touches on many points on which modern doctors would agree, including that the best exercise trains not just the body but also the mind; that it has to be convenient, otherwise people will simply not do it with the necessary consistency; that good exercise trains all the parts of the body equally; and it has to be possible to do it in a mild form, so that even children, those recovering from illness, or the elderly can benefit from it.

“Some people do not allow that one person is healthier than another, or that bodily condition exists along a considerable latitude, which we call health. Instead, these people say that health is one single and very precise thing that cannot be subdivided into ‘more healthy’ or ‘less healthy.’ But just as in the case of a white body, one seems to me to be less white and another more white, so too the healthy body seems to me to be more or less healthy.” (On Hygiene)

Even today too many people tend to think of “health” as a binary category: you are either healthy or not. Although Galen did not have a his disposal the sophisticated conceptual instruments of modern statistics, like the notion of a Bell (or “normal”) curve, he understood that health and disease come in degrees, and that what health looks like for someone may not apply to another, or even to the same person at different stages of life.

Since health and disease are best understood as a spectrum, argues Galen, so the doctor should act accordingly and provide age-appropriate advice for the maintenance of as healthy a state as possible. Fortunately, modern medicine is in fact catching up with such a framework, paying increasing attention to the peculiarities of individuals rather than treat a generic human being based on the model of a middle age white man, as it used to be until not that long ago.

“One must not decide who is healthy and sick simply by the strength or weakness of their functions. Instead, one should apply the concept of ‘in accordance with nature’ to those who are healthy, and the concept of ‘contrary to nature’ to those who are sick, such that health is a condition in accordance with nature that creates function, while sickness is a condition contrary to nature injurious to function.” (On Hygiene)

The concept of something being in agreement (or not) with Nature is crucial to ancient philosophy, and one that we would be do well to recover for the 21st century. Interestingly, the Greco-Romans applied it to both physical health (medicine) and spiritual health (philosophy). The idea, as Galen reminds us here, is closely tied to the concept of proper function of something, be it the human body (in the case of medicine) or the human mind (in the case of philosophy).

The concept of function in philosophy went out of fashion for a bit, because it was seen as rooted in outdated Aristotelian metaphysics. However, it actually originated before Aristotle, and we don’t need to buy into his concept of teleology to apply it. In modern terms, to live according to Nature means to take seriously what sort of biological and social beings we are, as a result of naturalistic evolutionary processes. There are certain things that are objectively good (or bad) for our body, and certain things that are objectively good (or bad) for our psychological and social wellbeing. To live according to Nature just means to want to stay healthy, body and mind. Why would anyone object to that?

[Previous installments: I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, XX, XXI, XXII, XXIII.]