What should you eat to be healthy? Well, the answer varies according to time and place, as we know from social media influencers who seem to constantly change their minds about what we ‘should’ or shouldn’t eat’. But who should decide what is healthy in the first place? According to some, only you can know what works for you and your body. Take a look at this:
‘Examine and observe yourself, deny yourself what harms you, and eat those foods which do you good: that is the best [advice] that medicine has been able to come up with for those who are in good health, to maintain it.’
Now, that sounds very sensible to me but, when you think about it, it’s quite revolutionary. It almost sounds like ‘intuitive eating’. What the author, the 17th-century French physician François Pinsonnat is saying is that you, the reader, should be the ultimate authority on what works for your body. In other words, you should be your own doctor where food is concerned. Pinsonnat, like many other European doctors, was influenced by the works of the controversial medical reformer Paracelsus. Paracelsianism truly revolutionised medicine in the 17th century, ushered in a new age of iatrochemistry, or chemical medicine, and accelerated the decline of Galenic medicine. It changed everything, from treatments for syphilis to the way people thought about food. So, in this text, I thought it would be interesting to explore Paracelsianism and its influence, taking food as a starting point. I’ll even tell you about a doctor’s weighing machine, which he used to measure what went inside the body… and later, what came out – and what that can tell us about digestion. Slightly gross, of course, but definitely interesting!
Becoming Your Own Doctor
I made a video a while back about how, in early modern Europe, digestion was understood, and, therefore, how people were advised to eat. Although doctors disagreed on some points, it was largely believed that the four humours – black bile, yellow bile, blood, and phlegm, were central to health, as illness was understood to be caused by an imbalance in the four humours. And then came Paracelsus. Now, if you’ve never heard of him or have no idea who he was, I definitely suggest watching my video on Paracelsus first for context – and I promise there are some weird and fascinating things in there, too. After you’ve done that, please come back and read this text.
In any case, suffice it to say that Paracelsus (1493-1541) was a highly controversial 16th-century doctor who decried university-trained physicians and their Aristotelian and Galenic belief systems. He believed that people should learn from direct observation and experience, not through books, and he spent much of his life travelling and getting into trouble with local authorities and physicians. During his lifetime, although many people were familiar with his doctrine, he wasn’t as well-known as he would be in the following century, since most of his writings were published after his death. And the reason why I’m so fascinated with Paracelsianism or rather Paracelsianisms, plural, is that people used his very eclectic works as a basis for lots of different things. His writings were a patchwork of alchemy, mysticism, natural magic, folk medicine, and reformist sentiment, not to mention some bizarre experiments and revolutionary chemical remedies, many of which were based on mercury and arsenic. His followers argued for the use of chemical drugs, leading the way towards modern pharmaceutics. Well, what about food, you might be wondering?
So, before Paracelsus, doctors relied on the humoral theory and Aristotelian writings to understand the natural world and how foods would interact with the body. This was based on a complex relationship between the four humours, their qualities of heat/cold and moist/dry, the correspondence between them and the four elements – fire, water, earth, and air – not to mention the seasons and the person’s constitution. But Paracelsus rejected this humoral framework of the world and replaced it with a chemical, or alchemical, system. Instead of the traditional four elements, three, the tria prima: mercury, salt, and sulphur. And all food should be considered in terms of these three elements.
Paracelsus wrote that everyone should follow a ‘regimen’, in the sense of a healthy lifestyle, to preserve their health. This was similar to what doctors had been saying for centuries. But, because Paracelsus rejected Galenism and the humoral theory altogether, he did not believe that people should follow the advice of university-trained doctors. In his ‘On the Long Life’ treatises, written around 1526 but published after his death, he described how everyone should know what they drank and ate because, through a regimen, so, through a healthy lifestyle, everyone could become their own doctor. Paracelsians even encouraged people to experiment in their own kitchens with furnaces and coal, distilling plants and doing a kind of proto-chemical analysis, to understand their components.
Paracelsianism and Digestion
So, Paracelsus rejected the humoral theory and Galenic medicine, but also the Aristotelian cosmology and the four elements – earth, water, air, and fire. Inspired by alchemy and several other traditions, from Neoplatonism to folk medicine, he replaced them with the three elements – sulphur, mercury, and salt. Some of his followers, such as Guinther von Andernach (1505-1574) tried combining these two frameworks and creating an equivalency between these different kinds of elements. As for Galenic, university-trained physicians, many of them attacked Paracelsians, calling them everything from charlatans to poisoners. But this traditional way of thinking medicine was being attacked from all angles in the highly competitive early modern medical marketplace, and Paracelsians were among many to criticise Galenic medicine.
A few generations after Paracelsus’ death, his followers, iatrochemists, or medical chemists, were refining and reshuffling some of his ideas – and removing much of the mysticism, magic, and astrological medicine that had been important features of Paracelsus’ work. For these Paracelsians, the tria prima – mercury, sulphur and salt – were not just elements, but rather capable of transforming things, of enacting chemical processes in the body. So, salt gave structure within the body, mercury, as the most volatile element, helped everything move inside the body, and sulphur was important for combustion, so for change inside the body. I know this sounds a bit vague, but let me tell you what that meant in terms of the digestive process.
Digestion had three parts: it transformed food, moved it around the body to where it needed to be, and became matter, and you can see how each of these is connected to one of the three elements, sulphur, mercury and salt. This was a completely new way of thinking about food and digestion, and it was very different from the previous understanding of the stomach as a cauldron and digestion as the process of ‘concocting’ or cooking food within the body. So, this is just an example, but it goes to show how Paracelsians were starting to think of the body and its processes and components in a completely novel way.
This was a period of transition between radically different ways of understanding the body. So, some doctors, such as the French Paracelsian Joseph Du Chesne, tried to reconcile old and new theories. In the traditional Galenic way of thinking, each food could be classified according to the humoral qualities of hot/cold and moist/dry. Of course, Paracelsus had rejected all of that, but it wasn’t immediately clear what the new way of understanding these processes should be. So, for Du Chesne, although he embraced Paracelsianism, he kept relying on these qualities to describe food. However, and this is what I find so cool about periods in which there’s a lot of change happening, he replaced the logic behind why certain foods were cold/hot or moist/dry from a Galenic framework to a chemical, Paracelsian one. Let me give you an example. Black pepper had been considered hot and dry for centuries – that’s why it was an ideal condiment for moist and cold salads, such as lettuce, to balance everything out. So, Du Chesne wrote:
‘The very spicy or piquant quality of pepper, which you can perceive in the taste and burning sensation on the tongue, comes from what chemical physicians call an aronic salt…’
So, he doesn’t question black pepper being hot and dry, he just changes the explanation behind it. And he goes on to say that this is why the ‘ancients’ had used it as a remedy, and agrees with the medical benefits. The reason behind this recommendation changed, though.
But not everyone was interested in balancing old and new. Some people were embracing chemical medicine wholeheartedly. Jan Baptist van Helmont, a Flemish doctor and Paracelsian, was interested in fermentation and he described digestion as the disintegration of food in the stomach through the activity of an acid. He didn’t mention heat, like physicians had for centuries, to explain how this process occurred. Van Helmont was studying acids and ‘alkalis’, as he called them, so you can see how there’s a big shift from the humoral framework of how the body works to a much more chemical way of understanding things. For him, digestion was central to understanding health and Galenic physicians had got it wrong since who else could know what agreed with their body but the person actually eating? Only they could know what worked for their bodies, depending on how they digested things. Another doctor, influenced by Van Helmont, wrote how, if people followed their appetite and paid attention to how the body digested food, they could pretty much eat anything they wanted. I wonder what readers felt when they read George Thomson praising ‘simple home-bred food’ and advising ‘moderation […] in all things’, rather than restricting yourself. For him, appetite should be your guide, as well as pleasure, so what foods people enjoy eating. Can you imagine how liberating that advice would be to patients, after centuries of regimens prescribed by doctors with instructions of what to eat, when, and in what order?
From Iatrochemistry to Iatromechanics (Or, a Rather Disgusting Weighing Machine)
Santorio Santorio (1561-1636) – a funny name, I know – was very intrigued about how digestion worked. He taught medicine at the University of Padua, and he had been influenced by Paracelsianism. While he wasn’t as contemptuous of ancient authorities as Paracelsus, he did believe that physicians such as Galen simply hadn’t had access to new technologies. He was very interested in mechanics – and especially iatromechanics or, ‘mechanical medicine’, as it were. He was fascinated with mathematics and statistics and how they could help doctors understand bodily processes, such as digestion. So, Santorio wrote how, for around thirty years, he would weigh himself several times throughout the day, using a weighing machine he devised (this is all between the late 16th and early 17th century, by the way). He compared the weight of what he ingested and what… came out of his body, for lack of a better word, and he was intrigued by the difference in both numbers. He thought maybe the body had other ways of excreting unnecessary things without people perceiving them, such as ‘insensible perspiration’.
Santorio’s medicine was focused on measuring things and essentially understanding the body as a machine, in a similar way as later physicians would conceptualise it. Just think of calorie-tracking nowadays, of watches that count steps, track heartbeats and whatnot. And, even though he still thought of the body in terms of the humoral theory, he was probably the first person to think that measuring physiological bodily functions was a useful way of understanding them and tracking health. Iatromechanics, or mechanical medicine, went on to explain the functioning of the body through mathematics and physics, influenced by the works of Isaac Newton and Rene Descartes. Still, it’s hard to imagine iatromechanics without iatrochemistry and Paracelsianism, without the idea that medicine could – and should – be reformed. Paracelsianism was eclectic and rich, and ideas could be combined in different ways to create new theories. Some physicians tried combining old and new ideas, as this was a time of transition, of both continuity and change. But, in terms of advice about diet people might find in books, there was a new focus on people eating what they believed agreed with their body. Physicians weren’t as strict about what foods to avoid, but rather suggested that readers be moderate. Francois Pisonnat, the doctor I mentioned at the beginning of the article, maintained that everyone should try to become their own doctor, offering very simple, sensible advice.
Final Thoughts
Paracelsus himself didn’t create a new dietary system, even if he did create a new medical system. But, through his ideas about how to understand the body and how to integrate chemical remedies into medical practice, he was pivotal in changing how people thought about health and the body. He also bolstered criticism against the humoral theory and Galenic medicine, and so empowered others to reconsider how medicine should be practised. His followers selected which parts of his eclectic writings they were interested in, sort of ignored the rest, and developed their own theories to fill in the gaps left by the controversial Paracelsus, often following their own interests and experiments. These Paracelsians brought about modern chemistry, combining the chemical remedies developed by Paracelsus with a focus on the chemical processes happening inside the human body. And, soon, iatrochemistry opened the door to iatromechanics and a new way of thinking the body in terms of a machine. Of course, in hindsight, some of their experiments may seem weird or funny. But they were gradually breaking with Galenism and rethinking how the body worked. Plus, their advice for readers to trust themselves and their intuition must have been liberating to hear. Thank you and see you next time!
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References
Joseph Duchesne, Le pourtraict de la santé (1620).
Paracelsus,A Book Concerning Long Life, ed. by A. E. Waite (1894, written ca. 1526).
Paracelsus, The Herbarius of Theophrastus [Paracelsus], Concerning the Powers of the Herbs, Roots, Seeds, etc. of the Native Land and Realm of Germany (1993, written ca. 1520).
François Pinsonnat, Régime de santé pour se procurer une longue vie et une vieillesse heureuse (1686).
Santorio Santorio, Ars de statica medica (1614) – translated as Medicina Statica, or Rules of Health (1676).
George Thomson, Orthomethodos Iatro Chimiche, or the Direct Method of Curing Chymically (1675).
Jan Baptist van Helmont, Oriatrike or, Physick Refined (1662).
Further Reading
Jean-Louis Flandrin and Massimo Montanari (eds.), Food: A Culinary History (1999).
Christopher Forth and Ana Carden-Coyne (eds.), Cultures of the Abdomen: Diet, Digestion, and Fat in the Modern World (2005).
David Gentilcore, Food and Health in Early Modern Europe: Diet, Medicine and Society, 1450-1800 (2016).
Bruce Moran, Paracelsus: An Alchemical Life (2019).
Andrew Wear, Knowledge and Practice in English Medicine, 1550–1680 (2000).
