Galen and the World of Knowledge

"Yes, this is a purely academic book—although the writing is not. The book I’m writing at the moment is about the brain and how we know what we know about this amazing structure. I needed to understand some of the earliest studies into brain function, in particular those by Galen, who did a series of remarkable and extremely distressing experiments proving that the brain controlled movement. These were public events, not laboratory studies. This is something Stephen Shapin talks about—scientists have to find a way of convincing other people that their results are valid. As the Royal Society’s motto says, ‘Nullius in verba’—don’t take anybody else’s word for it. Galen did his experiments in front of an audience to prove to the great and the good that the brain, not the heart, controlled movement. These experiments were on live pigs, and were extremely distressing. I was both horrified and astonished by the audacity of Galen and by the power of what he showed. Interestingly, it didn’t resolve the question of whether the heart or the brain was in charge—it would be another 1500 years before that was finally settled. And we can still see the traces of this argument in the words we use in English—‘heartfelt’, ‘broken-hearted’, ‘spoke from the heart’. The argument lives on in our language and in our thinking, a kind of intellectual fossil. This book shocked me by showing what an amazing thinker Galen was. I had this vague idea that his main legacy was the concept of the four ‘humours’, which dominated medical thinking for 1500 years or so. In fact, Galen wrote on all sorts of areas, not just medicine. He was a leading philosopher of the first and second century AD and he had a fantastic library—much of which has been lost, sadly. There’s a fascinating chapter about his lost library in the book. The chapter on Galen’s pig experiments is by Maud W. Gleason and is called, “Shock and Awe: The Performance Dimension of Galen’s Anatomy Demonstrations.” She’s absolutely right, that is exactly what it was: a performance. She also points out that there’s one character completely absent from Galen’s descriptions of what he did: the pig. What should have been at the centre, he doesn’t describe at all. One explanation is that he found the experiments extremely distressing. He said he couldn’t do these experiments on monkeys because their expressions were too distressing, too horrible. This raises a general question about our morality and that of people in the past. Surely these people must have been heartless beasts – how could they go along and watch Christians being thrown to lions or people hacking each other to death? And yet, of course, they were fundamentally no different from us. Galen had initially served as a surgeon to the gladiators so he knew all about terrible wounds and their consequences—that’s how he discovered that the recurrent laryngeal nerves control the voice. Gleason’s close reading of Galen’s work shows the complexity of the ideas and the events that were involved; it provides what historians call a ‘thick’ description by putting the work into its social and cultural context so you can understand it more. Yes, science is part of culture and is affected by other aspects of society. The metaphors that we use to explain things are taken from culture and, in particular, from technology. I try to describe scientific problems as people saw them at the time, without the benefit of modern knowledge. In the books I have written I describe people in the past who are struggling, either in a scientific context or, in the case of my books about the French Resistance, in a military-political context. They didn’t know what the outcome was going to be. To describe that uncertainty to the reader—and to explain why people thought the things they did and did the things they did—the writer needs to try and forget what’s to come. Following this kind of rule means that means there are certain things you can’t say, which can make matters difficult. I wanted to write T he Egg and Sperm Race because I got obsessed with a 17th century microscopist called Jan Swammerdam. I really wanted to write a biography about him but it became apparent that no publisher—not even an academic one—was interested. Then I thought about a popular science book, focussing on one aspect of his work, which was about the importance of eggs in what we now call reproduction. The book is about the discovery of egg and sperm but it also extends into ideas about where animals like insects come from. When I write I try to put myself back at the time and to understand the choices that people made—whether they were political choices about what they were going to do, moral choices in the case of war, or scientific choices. Also, in the case of science, why people believed the apparently outrageous things they did. Because one thing I always emphasise to students is that you’re not allowed to think people in the past were stupid. Most of the people I write about were much smarter than we’ll ever be. And yet they often believed all kinds of nonsense. “Science is not just a story we tell ourselves, it is an increasingly accurate representation of how the universe works.” Why was that? How could these very clever people believe things that we now consider to be so palpably untrue? How did we get to where we understand things today? What was the process? To do that, you need to try and reconstruct what people thought; one of the ways of doing that is to banish all the words and concepts which come from later on. So, in the seventeenth century book I couldn’t talk about ‘reproduction’ because it wasn’t a seventeenth century term—people talked about ‘generation.’ That is what we would call ‘reproduction’ and ‘development’ rolled together in one word. Similarly, you can’t talk about heredity before the 19th century. Heredity only takes on a biological meaning in the 1830s—people didn’t have a word to describe the relationship between parents and offspring. Then you realise that there’s a reason why people can’t see things—they don’t have the words, the ideas. The concepts aren’t there and therefore you can’t think them. I was very fortunate and lived for 18 years in Paris. I went with absolutely awful French and ended up pretty much bilingual. One of the things I realised is that when you can speak another language, you can think things you can’t think in your mother tongue. Words and thoughts are interconnected. That’s one thing that I tried to bring over in my books, by trying to look at what people thought at different times and how the ideas and concepts either limited them or finally enabled them to understand things in a richer way. That’s the contradiction! On the one hand I am very confident that I know what I know! However, I know that in the future people are going to look back and say, ‘How did they get it so wrong?’ I guess that, just like Newton wasn’t wrong in terms of the laws of motion, that reanalysis—that reinterpretation—is going to be partial. However there are massive challenges ahead. Physicists don’t know what 95% percent of the universe is made of, and we have very little understanding of how the brain works. So at the macro and the micro level, our ignorance is profound! There’s a long way to go."