 Hi, I'm Peter Adamson and you're listening to the History of Philosophy podcast, brought to you with the support of the Philosophy Department at King's College London and the LMU in Munich. You've probably heard of the placebo effect, in which patients respond positively to dummy medications like sugar pills. While there is controversy as to just how strong the placebo effect is and what causes it, some studies suggest that it can be astonishingly powerful. For instance, when it comes to pain relief, placebos may be half as effective as actual pain medication. This helps to explain the popularity of alternative medicine. Crystals and homeopathic remedies presumably don't affect the body any differently than sugar pills, but they still work insofar as they are effective as placebos. The effect also explains a lot about the history of medicine. It seems at first perplexing that doctors were respected experts in pre-modern societies, from ancient Greece and India to the medieval Islamic world, given that these doctors largely had no idea what caused diseases or how they could be cured. True, this was in part because they could sometimes offer real treatment. Cataract eye surgery was performed successfully in the Islamic world, for example, and effective therapies were also identified by trial and error. Much of the benefit offered by these early doctors, though, would have derived from the placebo effect. The drugs that were prescribed by a doctor like Galen or Avicenna would rarely pass muster in a modern trial, but merely receiving attention from such confident and renowned experts no doubt helped their patients nonetheless. We congratulate ourselves with having come a long way since these bad old days, now having learned to compare drugs with placebos in blind trials, but it turns out that the placebo effect was not unknown to pre-modern medicine. In the 16th century, Cardano, who counted medicine as one of his many interests, noted that a magic charm made dull a toothache simply because the sufferer believes in its power. And why not? When it came to matters of health, the people of this period needed all the help they could get. The Renaissance has been called a golden age of disease, beginning with the Black Death in the mid-14th century and featuring other bleak milestones like the outbreak of syphilis in Europe at the end of the 15th century. Italian city-states responded with genuinely useful measures, like the founding of hospitals. These were at first little more than hospices for the poor and sick, but increasingly acquired competent staff. Visiting Italy in 1511, Martin Luther, not an easy man to impress, marvelled that the hospitals were built like palaces, that best food and drink are given to everyone, that nurses are diligent, that doctors learned. The vectors of contagion were not yet well understood, though physicians did figure out that syphilis was sexually transmitted. Still, the sheer fact of contagion was obvious. This led governments to decrease sanitary regulations, including the 40-day seclusion for newcomers to trading cities like Venice, Pisa, and Genoa, which gives us the increasingly familiar word quarantine. There was even a controversy in late 16th century Rome about the safety of drinking water from the Tiber River. This being the Renaissance, the arguments turned on evidence from antiquity, as doctor historians debated whether aqueducts had been built to provide cleaner water, and wrote treatises on the health benefits of the Roman baths. Humanist expertise on ancient texts, including ancient medical literature, was one factor that made Italy a leading medical center in the Renaissance. Another was the university system. Bologna had always been associated with medical training, and the subject was also important at Padua, Ferrara, and elsewhere. These universities drew aspiring physicians and scientists from all over Europe, who then returned home, to spread medical learning in their home territories. To give just one example, the medical historian Nancy Suriase has calculated that out of 37 professors of medicine at the University of Erfurt in the 15th century, 16 had studied in Italy. This is comparable to the standing of Italy in legal scholarship. Indeed, nothing epitomizes Renaissance Italy's university culture better than the dispute over the relative superiority of these two disciplines, law and medicine. It was a question that attracted the attention of such sharp thinkers as the Averroist, Nicoleto Vernia. He took the side of medicine because of its close relationship to philosophy and its exemplary status as an application of proper scientific method. Another partisan of medicine, Bartolomeo Fazio, said that medicine is better than law because it involves an understanding of natural causes. What could be more ingenious, he asked, than to grasp through reason the composition, structure, order, and the very causes of the diseases of our bodies. Of course, we've seen many times in this podcast that the study of the law, too, had intimate connections to philosophy. But Vernia was not wrong to emphasize the dependence of medicine on the philosophy of nature. Learned medicine in the Italian Renaissance drew extensively on the 2nd century AD doctor Galen and authors influenced by him, especially figures from the Islamic world like Arasi, Imnocina, and Imrushed, known respectively in Latin as Razes, Avicenna, and Averroes. Like them, Renaissance physicians remain committed to the basic principles of Galenic medicine. Health and disease are determined in large part by the balance and lack thereof of the four humors, blood, phlegm, black bile, and yellow bile. This can be maintained and restored in an emergency through interventions like drugs or bloodletting, but preferably through a healthful regime, which ideally should be tailored to each patient by his or her doctor, given the wide variation in individual bodily constitution. Renaissance also plays a role, as already taught by Hippocrates, in the treatise, Airs, Waters, and Places. Thus, doctors spoke of six factors that could be manipulated in order to preserve health – air, food and drink, exercise, sleep, evacuation, and emotional states. The points of contact with philosophy are many. The four humors have the properties associated with the four elements. For instance, yellow bile is hot and dry, like fire. Psychological and emotional health is related to ethics. The role of environment connects medicine to meteorology, which is why the aforementioned debates over issues like contagion and clean drinking water invoked ideas from Aristotelian philosophy. It should be said, though, that the partnership between philosophy and medicine was not always an untroubled one. Back in the 14th century, Pietro d'Abano had written a work called Reconciler of the Differences between Philosophers and Physicians, which itemizes and discusses the clashes between Aristotelian philosophy and Galenic medicine. One example was the different list of powers or faculties considered in medicine and in philosophical anthropology. Galenic doctors spoke of the so-called vital faculty seated in the animal spirit, and of spirit or pneuma coursing through the body from its origin in the heart. It was not so clear how to fit such ideas into the psychological theory outlined in Aristotle's treatise On the Soul. Furthermore, it was not usually thought that medicine was actually part of philosophy, like physics, meteorology, zoology, or botany. Medicine might take over principles from all of these disciplines, but it is an applied science, whereas the parts of natural philosophy are theoretical sciences directed toward the pursuit of pure knowledge and not toward practical action. One might compare the relation between architecture and mathematics, the former being concrete, the latter abstract. Zabarella captured the relationship as follows. There cannot be a good physician who is not also a natural philosopher, but there is a difference between them. Medicine is concerned only with accomplishing its purpose, while natural philosophy has no purpose to accomplish, but is only knowledge. This contrast lay behind the frequent motto, where the philosopher leaves off the doctor begins. In other words, the physician carries forward and applies what he has learned from physics. This idea was reflected in the teaching curriculum. The university-trained doctor would have studied physics or natural philosophy, and before that, logic, before coming to their specialist subject. Piazzo d'Abbano explained why doctors needed to become acquainted with these fields. Logic, since it is the condiment of all the sciences, just as salt is of food, and natural philosophy, since it shows the principles of everything. Doctors with this sort of training considered themselves to be far superior to mere practitioners like community surgeons and apothecaries who simply applied the deliverances of past experience without any conception of an underlying causal theory. In this too, the university physicians were echoing Galen, who criticized the ancient empiricist medical school for refusing to offer rational explanations for the efficacy of their treatments, and just blindly doing whatever seemed to work in the past. Here we might think is one reason that the bad old days were so bad when it came to medicine. University doctors were trying to learn from old books when they should have been abandoning the false theories in those books and learning from experience. But as usual, things are a bit more complicated. For starters, it was a matter of dispute which books the learned doctors should be reading. A pure humanist approach would encourage the exclusive study of Greek medicine, and some medical authors did take this approach. Nicolo Leoniceno, at the beginning of the 16th century, wrote a treatise called On the Formative Power, which rigorously adhered to Galen's account of embryology and mentioned authors who wrote in Arabic, like Varouis, mostly in order to disagree with them. Thus in his study of this work, modern-day scholar Hiro Hirai has concluded that Leoniceno was motivated by strong anti-Arabism and a steadfast love for the Greek sources. A particularly good illustration of the way Renaissance medical writers used ancient literature is supplied by the study of plants. Several cities saw the literal planting of botanical gardens, and at Padua there was a professorial chair just for materia medica, in other words for the study of plants and other ingredients used in drugs. No effort was spared in the ambition to recreate classical drug recipes, a project that called for skill in philology as well as botany. What exactly were various obscure Greek words for plants referring to? Some authors look back even further, writing about plants and stones mentioned in the Bible and discussing their healing properties. One of these was David de Pomi, born in Spoleto in 1525 and educated in Perugia. He wrote a lexicon of biblical stones, including a lengthy discussion of hyacinth, the stone not the flower, and its power to ward off the plague. I highlight his contribution in part because he was Jewish, a reminder that in Renaissance Italy, as in the Islamic world, Jews were strongly associated with the study and practice of medicine. Speaking of the Islamic world, for all the classicism of this period, most authors found it impossible to escape medical literature written originally in Arabic. The curriculum in Bologna called for the study of Arasi and Avicenna, along with Galen, and both authors were cited abundantly in Renaissance tracts on medicine. To cite again the historian Nancy Syriasi, she counts at least 60 Latin printings of Avicenna's canon from 1500 to 1674, with a particularly impressive case being the 1523 five-volume edition of Avicenna, together with later commentaries. One medical author, Sebastiano Preciani, went so far as to stipulate that any physician worth his salt should master Arabic, as well as Greek and Latin. That message didn't get through to a scholar named Andrew Graziolo, who offered a new translation of Avicenna without actually learning the original language, but this just goes to show the extent to which Arabic texts were absorbed into the world of Latin learning. This can also be seen from the frequent quotation of such authors. Take the anatomist Beringario di Carpi. He quotes Avicenna more than 1000 times and considers Rasi to be an authority second in importance only to Galen. But Beringario's field of anatomy demonstrates that authors of this period were interested in observation as well as books. It could hardly have been otherwise, since their reading of ancient and medieval sources emphasized the importance of empirical investigation in medicine. Galen prided himself on this. As just mentioned, he criticized the pure empiricists for their lack of theory, but he was also critical of pure rationalists, who ignored the hard-won fruits of experience and tried to work out all their treatments from first principles. The same message could be found in Avicenna, whose subtle account of scientific experience encouraged the simultaneous use of observation and causal theory. He even gave an example from pharmacology, namely the purging effect of a plant called scamini to illustrate how this works. Renaissance anatomists took this advice very much to heart and to all the other organs as well. Human bodies had not been dissected for research purposes since ancient Alexandria, well before Galen himself. But now this practice began again, with an annual anatomical demonstration established in Bologna already in 1405 and in Padua by the middle of the 15th century. Dissection, and unfortunately also vivisection, was also performed on pigs, which were thought to be anatomically close to humans, and on other animals as well. Beringario di Carpi first cut his scalpel, though hopefully not his teeth, on the corpse of a pig, under the instruction of none other than Aldus Manusius, the pioneer who printed the works of Aristotle in Greek. When he came to write on anatomy himself, Beringario emphasized the role of observation in this discipline, saying that it ultimately trumps the role of authority. While professing to be guided by, as he put it, sensation, the authority of the divine Galen, and various reasonings, he would not accept an anatomical claim found in Galen if he found contrary evidence in actual dissected bodies. This critical attitude was taken further by the most famous anatomist of the Italian Renaissance, Andreas Vesalius. He was actually Flemish, but became professor of surgery in Venice after first learning his trade in Paris. His work on the fabric of the body is distinguished by its itemization of mistakes committed by Galen. In keeping with the spirit of the age, Vesalius proclaimed that study of anatomy was only just recovering from a long period of ignorance during the Middle Ages. Apart from the obvious step forward that anatomical treatises were now based on actual anatomical dissection, Beringario and Vesalius made another breakthrough by including detailed anatomical illustrations in their works. Vesalius explained this in terms that should seem familiar to us after the previous episode, saying that mathematical treatises are much easier to follow thanks to the diagrams they include. Indeed, the case of anatomy shows us that medicine and artistic production could go hand in hand, just like mathematics and art. Alberti's On Painting, which we talked about last time, says that artists must become acquainted with the structure of the human body, since when we paint a person, we should first think about where the bones would be, then the muscles, and then re-clothe these with skin and flesh. The woodcut images found in Renaissance anatomical works are remarkable for their artistic ingenuity and imagination. Beringario's treatises already include arresting depictions of people calmly spreading open the skin of their torsos so that we can look inside, while the skeletons and muscle men of Vesalius strike dramatic poses as their flayed skin hangs from an elbow or hand. These illustrations are not just a substitute for the direct observations students could enjoy, if enjoy is the right word, during an anatomical display. They are idealizations, which make it artificially easy to see bodily structures that would be very difficult to make out in the messy gore of an actual autopsy, and which also convey the wondrous intricacy of the human body. Specialists in anatomy never tired of emphasizing the perfect design of the body, a theme they could find in their ancient sources. Galen's treatise on the usefulness of the parts is a lengthy paean to the exquisite functionality of human bodies, and Aristotle's zoological writings are notorious for their commitment to the idea of final causality, animal organs are shaped to pursue the purposes of the animal. This idea was central to the project of Hieronymus Fabritius, who was professor of anatomy at Padua beginning in 1565. As a good Aristotelian, he was interested in the parts of animals, not just humans. He published studies of individual animal organs like the eye, larynx, and ear, which express his Aristotelian belief in the functionality of these body parts. Indeed, he said himself that this distinguished his approach from that of Vesalius, who had been content to expose, literally, the structure of bodily organs without investigating their function. We can see Fabritius's approach as an application of the scientific method articulated at Padua by Zabarella. Anatomy is treated as a true empirical science, which begins with observation and works towards causal principles that explain what has been observed. In this case, this means determining the final cause, that is, the purpose or goal, of each organ, which will then explain the details of its physical structure. The result is a discipline that, in Fabritius's words, constitutes the true and solid basis of the whole of medicine and the ultimate perfection and consummation of natural philosophy. Notice here again the implication that medicine depends on theoretical natural philosophy without really being a part of philosophy. That too is something familiar from Zabarella, who was at pains to distinguish inquiry conducted solely for the sake of knowledge from medicine proper, which is an applied discipline that aims to produce health in the patient. This would be the philosophical rationale for the aforementioned disdain that many learned scholars of medicine showed towards mere practitioners. But not all scholars took this attitude. One man who had a more hands-on approach, who made detailed case notes on his medical practice and his own troubled medical history, was Cardano. His works bring together themes we've already been discussing, like mathematics and medicine, as well as themes we have yet to tackle, like magic and astrology. I mentioned him in passing in this episode, but like the human body, he deserves much more detailed inspection. And we'll get into him next time here on The History of Philosophy Without Any Gaps.