Thinkers in the ancient world were as focused on preserving health as they were on curing illness. Despite the medical advances of Galen’s era, doctors still struggled to treat a variety of ailments, and they knew it was preferable to prevent illness in the first place. Sailing is a recurring metaphor in texts about regimen—diet, exercise, lifestyle—as it is easier to keep a ship steady than to right its course. Balance is important.
Doctors and philosophers alike were interested in a systematic plan for living and ascribed both a physical and a moral value to a proper regimen. Advice on living well is presented in different kinds of texts for expert as well as general readers, and the scientific, social, and ethical aspects of an individual’s regimen often bleed into one another. Galen considered himself a physician-philosopher, and such concerns occasionally overlap within his writings too.
A regimen provides a way to manage the external factors that can influence health. While much about the body is unchangeable, a regimen is within one’s control. Galen writes:
Everyone possesses all of the elements, according to Galen, but in most people, one or two are dominant. Too much or too little of any element leads to disease, but the external actions we take have the power to rebalance our internal systems.
Galen categorizes four different ways that our lifestyle brings our bodies into contact with the external world in his book Keeping Well: there are “things to be administered” (items we take in, such as food, drink, and air); “things to be removed” (excrement, urine, fluids purged through vomiting, venesection, etc.); “things to be done” (walking, riding, exercise, massage, sex, sleep, etc.); and “things to be applied” (anything that touches the skin, e.g., during bathing and anointing).
While the right proportion of these “things” is necessary, there’s no one-size-fits-all prescription, and the exact recommendations will be different for each person according to their individual needs. The balance is not static for each person either, and varies across the life cycle from childhood through old age. For Galen, the body responds and changes according to its environment and over time.
While Galen believed that a person’s activities affected their physical health, he also maintained that one’s mental state played a role. Internal emotions, too, can influence wellness, and he recounts cases of patients suffering physical problems caused by fear, anger, and grief. Cultivating the mind was just as essential as caring for the body, and Galen also wrote books on how to regulate emotions (Avoiding Distress and Affections and Errors, for example), and focused particularly on how to cope with unpleasant feelings in the face of loss or misfortune. While improperly managed negative feelings can have a deleterious effect on the body, a disciplined mind can also help when physical problems arise; Galen writes with admiration about the orator Aelius Aristides, an acquaintance with “a strong soul and a weak body,” whose mental strength buoyed his resilience in the face of illness. Galen understood that there was a connection between mind and body, and that this relationship was reciprocal.
Keeping Well, Galen’s most extensive description of an ideal approach to regimen, is a fairly lengthy book by his standards—he acknowledges this self-consciously in the course of his text. The great attention he devotes to what we now call “preventative medicine” is indicative of a regimen’s power. For Galen, many aspects of lifestyle were part of a continuum of wellness, from health maintenance to healing; food, for example, could be consumed for its ability to sustain well-being, or as a medication with an aim to heal.
Contemporary scientists are increasingly returning to such a notion, and it is now common for doctors to first recommend lifestyle changes prior to prescribing medication for conditions that can be improved in this way.
But in the ancient world, a prevention-minded approach played an outsize role in comparison with medicine today, in part because regimen held greater explanatory potential: ancient thinkers were unaware of germ theory, and disciplines like virology and microbiology still were centuries away. That Galen’s recommendations—based on his theoretical understanding of the humors and attentive observation of individual patients—frequently accord with the recommendations of present-day health experts makes his insights even more remarkable.