When it comes to medicine, do you think theory or practical experience is more important? This is a question that is central to modern medical education, and it was a conundrum that exercised the mind of one of the most famous physicians in the ancient world, Claudius Galenus, or as we know him today, Galen.

Born in 129 CE, Galen grew up in the Roman Empire at the height of its power and his birthplace, Pergamon (now in modern day Turkey), was at the time a major cultural and intellectual hub. He received his medical training in several centres in addition to Pergamon, including Smyrna, Corinth and Alexandria. At the age of 28, he returned home from his travels and was appointed to the prestigious role of physician to the gladiators. This post allowed him to expand even further his knowledge of trauma and human anatomy. Four years later, Galen decided to travel to Rome where he found fame and success, eventually becoming the personal physician of the imperial family. He continued to practise, write and move in the highest tiers of Roman society until his death in around 216 CE.

Thus, even in his own lifetime, Galen was something of a medical superstar, but his writings were to be his legacy, for they would influence the way medicine would be taught and practised for the next 1,500 years. Indeed, Galen is thought to be the most prolific author of antiquity, producing around 600 books, of which only around one third survive.

In addition to being a practitioner, Galen was also a theoretician and the relative importance of the two was a theme in many of his writings. In one of his many books, On Medical Experience, Galen makes a number of arguments for the value of experience over theory, but perhaps most convincingly he uses two examples that are immediately familiar to readers. First he evokes a piece of hard-won experience to which most will relate — the hangover.

You know that men taken as a whole, of whatever type they may be, do not feel bound to examine into the nature of wine, but that they know perfectly well that too great indulgence in drinking wine is harmful.

In other words, you do not need too much theoretical understanding of the metabolic effects of alcohol on the human body to appreciate its toxicity, if you have ever drunk too much.

‘And so it is with mushrooms,’ he continues, as he draws upon another potential form of poisoning.

One finds that the learned man who discourses on the natures of things, knows their nature. But if any mushrooms are placed before him, he does not know which are edible and which are not, whereas the country-dwellers can distinguish between them since they are familiar with them and see them constantly, and even the children know them, to say nothing of their elders.

Just as with alcohol, when it comes to the toxic properties of fungi, theory is a poor teacher when compared to experience.

Galen concludes his argument for the superiority of practical experience over theory by stating:

And in short, we find that of the bulk of mankind each individual by making use of his frequent observations gains knowledge not attained by another… [E]xperience and vicissitudes have taught men this, and it is from their wealth of experience that men have learned to perform the things they do.

Despite these vivid examples, Galen was also able to present equally compelling arguments for the pre-eminence of theory over practice, and his works, though extensive and varied, draw upon both. Indeed, one of the threads running throughout his vast work is his equal recognition of the importance in medicine of theory and practice. He was a practitioner of medicine and surgery, but he was also a researcher, reliant on both the theoretical work of his forebears, such as Hippocrates, and his own experiential learning and experimental research. Although Galen placed great store in the Hippocratic writings, which were already more than 500 years old when he was studying them, he was keen not to take things at face value. Galen believed that the practice of medicine would advance through a combination of reason and experience, adding for good measure,

The surest judge of all will be experience alone, and those who abandon it and reason on any other basis not only are deceived but destroy the value of the treatise.

As one of his translators concludes: ‘In the ancient conflict between theory and practice, Galen wishes to lay claim to the best of both worlds.’

So, in answer to the question, ‘theory or practice?’ Galen would have said both, but he might also have asked you to consider whose advice you would take when deciding whether to eat a mushroom or not — one well-versed in theory but with no practical experience, or one who’s tried them before?

© Allan Gaw 2016


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Lessons from the History of Drug Research

What can we learn from the past that may be relevant to modern drug research?

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