The war of images

1906 was the first time a Nobel Prize was awarded to two scientists. The prize for medicine was shared by the Spanish Santiago Ramón y Cajal and the Italian Camillo Golgi who earned it with their groundbreaking discoveries in the research of the structure of the nervous system. Although they worked in the same field of science, the first time they ever met was at the award ceremony in Stockholm.

Traditionally, each laureate is given an honorary lecture in which he can describe his work in detail. Golgi’s lecture was one day before Cajal’s and some controversy between the two was to be expected. Even though both were doing research on the anatomy of nerves, each of them had his own theory on how the nervous system was built and how it functioned. Despite the fact that both of the scientists were polished professors, one could sense a strongly skeptical attitude towards some of the main conclusions each of them argued for during their presentations.

As a child, he blew up his neighbor’s door with a cannon

In the early years of his life, Santiago Ramón y Cajal showed little promise of becoming one of the most highly esteemed anatomists in the history of neuroscience. He was a very troublesome child and was expelled from several schools due to his low grades and disobedience. Once, when he was eleven, he even ended up in jail. During summer holidays, he and his local gang, of which he was also the leader, made a real, working cannon from scrap metal. Naturally, the youngsters had to test it and the neighbor’s new garden door was the perfect target for this teenage artillery.

After the explosion, which was truly devastating, the neighbor complained to the mayor who sent an officer to bring the eleven-year-old Santiago into custody. Of course, his father was furious with him so he insisted on making this outrage his son’s final lesson and Santiago had to spend four days inside a smelly, dirty cell on nothing but bread and water. His mother used the guard to sneak in some food from home, but he still had to spend those nights and days in solitude.

The severe punishment was obviously not enough to teach him a lesson, though. He and his gang constructed another cannon, but this one already blew up while it was being tested. They were experimenting with other ballistic methods which could have very easily ended with a tragic result. One time, the barrel filled with gunpowder blew up near Santiago’s face, but he only got an eye infection and a permanent scar on his iris.

However, Cajal was not only technically inclined, but also had great interest in drawing. In fact, he wanted to become a painter. His father, a university professor of anatomy, fused his son’s love of drawing with his enthusiasm for anatomy and got him interested in biology. The two supposedly stole corpses from a nearby cemetery then dissected them, and the youngster used his talent for drawing to learn the technique of anatomic illustration.

In his memoirs, Cajal remembered this unusual period of his life which had probably contributed the most to his decision to become a scientist later on: “In front of the great anatomic desk which covered the dissecting table the brain as well as the stomach first shriveled in disgust. But they soon became used to it, and the corpses did not lead me to sad thoughts anymore, but reminded me of wonderful creations of life.”

After finishing medical school he joined the Spanish Army as a doctor for a couple of years and spent a year on Cuba. There, he was unfortunate enough to contract malaria as well as tuberculosis, but this did not prevent him from marrying and having seven children after he returned. In 1881, he became a professor in Valencia, but it was several years earlier that he had used his modest savings to buy an old microscope with which he studied the structure of tissues and similar biological preparations.

A method successful because it rarely works

In Madrid in the year of 1887, when he was thirty-five, he met a psychiatrist friend who had just come back from Paris and brought with him a sample of brain tissue, prepared according to a special method that had been invented by Camillo Golgi fourteen years earlier. Cajal was putting together a book on the techniques used in histological research which he wanted to accompany with his own illustrations. He had a lot of difficulties with the studies of the nerve tissue, so his introduction to Golgi’s new method was a true revelation.

The essential advantage of Golgi’s neuron staining method was that it almost never worked. It only colored one in approximately a thousand neurons which was extremely important for the observation of the structure and the functioning of nerve tissue. This made it possible to observe a single neuron in a mass of neurons and examine its structure in detail. This is something like having a bowl of pasta in which most of the spaghetti are transparent and invisible and one or two are colored dark so you can examine them closely even if they are mixed up with other, invisible strings of spaghetti.

After learning about the new “black reaction” method, as Golgi’s staining technique was called, Cajal moved the focus of his research and came to many key conclusions about the structure and functioning of the nervous system. Before, it was believed that the brain was a mass of intertwined connections constituting networks, while Cajal, with his anatomical studies, demonstrated that the nervous system was also made of individual cells which were called neurons and through which nerve signals traveled.

Even though both scientists used the same staining technique that Golgi had developed, their conclusions were diametrically opposed. The principal argument was whether neurons were completely independent and separate cells or whether they formed some sort of a homogenous network.

The objectivity argument

When it came to interpreting their argument, drawings were of key importance. The difference between them was that they had different opinions about how a scientist should ensure that he gets as reliable data as possible on the functioning of nature. Basically, they were waging a kind of a war of images. They both criticized each other for not being objective: Cajal defended an unaltered representation and accused Golgi of intentionally interfering and modifying his descriptions, so that they corresponded to his own theoretical preferences.

Cajal was convinced that a scientist should only copy what he sees in as much detail as possible and try not to interfere with the image. According to him, a scientist should be like a camera, only transferring onto the image what he sees under the microscope. Golgi, on the other hand, was of the opinion that a scientific drawing should demonstrate the essence of the phenomenon it is describing and try to understand it. The duty of the scientist was supposed to lie in modifying a drawing, so that it reflects an ideal example, even though it might be composed of several examples of what can be seen under the microscope.

Lorraine Daston, a director of the Max Planck Institute for the History of Science in Berlin, and Peter Galison, a professor of history of science at Harvard University have emphasized in their book Objectivity (Zone books, MIT Press, 2007) that in trying to understand this interesting episode from the history of science it is necessary to realize that both scientists argued in good faith and that their sincere personal integrity should be viewed as the ideal of the true scientific approach. Both were convinced that their methods and consequently their conclusions were in accordance with the strictest principles of scientific work, so they firmly stuck to their beliefs.

According to the historians, who develop and thoroughly explain their statement in the book, even scientific objectivity has its history. The scientists of the Age of Enlightenment, for example, felt obligated to gradually improve their drawings of plants and animals and ended up creating much better and more beautiful images than those they could observe in the nature. Golgi, who followed this enlightened ideal, incorporated the interpretations of what he saw in his drawings of the nervous system because he thought that was objective an made perfect sense.

However, as the historians clearly demonstrate with numerous examples, some scientists gradually began to look upon such practice as a sin. Sometime in the middle of the nineteenth century a new ideal of pursuing objectivity appeared, one which was also defended by Cajal. “Let nature speak for itself!” became the motto for understanding scientific activity and the main question became how to describe and represent the world without creating the feeling of the presence of an actual observer. It was because of the pursuit of different ideals of how to portray objectivity in science that the researchers began their dispute and the so-called war of images.

She's blind, but she sees

Defective gas water heaters can be extremely dangerous. A woman from England called Dee Fletcher had the misfortune to find this out herself in 1988 when she was taking a shower in the new house she and her husband Carlo had bought in a small village north of Milan. Unaware of any possible dangers she decided to freshen up in her new bathroom, carelessly started to shower, never even thinking of the possibility that deadly gasses were filling the air. The room was not well aired, so the flame did not have enough oxygen to burn which lead to the accumulation of the deadly carbon monoxide.

This gas is very dangerous because it has no scent, so one usually does not sense its presence until it is already too late. Unfortunately, this is exactly what happened to Dee. She lost consciousness and would have died soon after if Carlo had not returned home at that very moment. He immediately started to resuscitate her and quickly got her to the nearest hospital where they saved her life. At first, nobody knew how much time her brain had been deprived of oxygen, which could have caused permanent damage. The brain is the organ which suffers the most rapid deterioration when it is not provided oxygen. A few minutes of interrupted oxygen supply are enough to cause brain cells to start dying.

She can’t distinguish objects, but she sees their details

When Dee woke up in the hospital the doctors were quick to realize that the carbon monoxide poisoning did not go by without leaving consequences. Even though she could speak normally and understand what others were saying, she could no longer see. The doctors’ first diagnosis was that the poisoning had destroyed the sight center in the brain, but they had to change their opinion in the next couple of days as Dee started to show signs of sight. When Carlo came to visit her she mentioned that he was wearing the same sweater as the previous day. She also knew that outside the sky was clear, and that the flowers in her room were red and blue.

When her mother arrived from England she did not even recognize her when she first came into her hospital room. It was not until she heard her voice that she was gladdened by her presence. On the other hand, Dee had no difficulties with handling objects and recognizing colors. The next day when she and her mother were having a cup of coffee something even more unusual happened. She was surprised at her own ability: “You know what’s strange, mom? I can see the little hairs on your arms perfectly clearly!”

Her mother was beside herself with joy when she heard her say this, because she thought that her daughter would gradually regain her sight after all, but the happy moment was only short-lived. It became evident that Dee could no longer recognize the shape of the objects she was looking at. Even though she could discern the color and texture of an object, she could not figure out what kind of an object it was. The poisoning had caused Dee to lose only a part of her ability to see. Although she could still see the colors and the structure of the surface of individual objects, she could no longer make out their shape.

Blind to shapes

Her blindness was later studied by English neurologists who discovered that she was still able to distinguish colors very well. She was capable of recognizing very small nuances in the shades of individual colors. She could also tell if an object was made of plastic, wood or metal, but she could still not discern shapes. When she was shown parallel lines on a computer screen she had no trouble with recognizing the pattern she saw, but she could not determine whether the lines were vertical or horizontal.

It is necessary to state that she had no previous problems with her eye-sight which, of course, could have caused her to have blurred vision like someone who is very short-sighted. Her vision was completely clear and sharp which is supported by the fact that she could recognize from a distance the colors and patterns that myopic people could not see. After thorough examination it became clear that Dee was only blind to shapes, but otherwise had perfect vision. It does not matter what the shape in question might be, Dee can not recognize it. However, she does not have a problem with interpreting what she is seeing, but with the process of looking itself. It is not a matter of her brain recognizing shapes, then failing to interpret them and link them to words. Dee simply can not see shapes.

When doctors asked her to draw an apple from memory she did very well, but when they gave her an image of an apple to copy, all she was able to draw were indistinct scribbles. During the first years following the accident she also had nightmares which were quite different than the usual ones. For her, the nightmare began when she woke up. When she dreamed, her sight was fine, but when she woke up she came back into her unusual shapeless world.

The medical term for the condition in which people are no longer capable of recognizing things that surround them, even though their eyes function normally, is called “agnosia”. The term was coined at the end of the nineteenth century by the, at the time still unknown, neurologist Sigmund Freud who used it to describe patients who had difficulties with establishing the meaning of what they saw. Of course, there are many different kinds of agnosia depending on which part of the patient’s brain is damaged. In medical literature, many types of this “conceptual blindness” have been described, some of which are also quite exotic, such as amusia, in case of which the patient has no ability to recognize music, even though his hearing is intact.

Dee’s condition is a case of visual form agnosia. However, it is not a classic example of the disease. Neurologists were surprised to discover that Dee was completely capable of picking up a pencil, though she was not able to recognize its form. Regardless of how the pencil was placed on the table or which direction it faced she could pick it up effortlessly which implied that she did perceive shapes somehow, but was not aware of it. If she were completely blind to shapes she would not be able to pick up the pencil as easily.

Do people have two separate brain mechanisms for seeing?

When researchers delved deeper into Dee’s case, they became increasingly aware of the fact that Dee could still respond to the outside environment very well, as if she had perfectly good eyesight, but at the same time could not understand what kinds of forms she was actually seeing. What did this mean? Researchers made the hypothesis that people do not only have one, universal mechanism that gives meaning to what we see or, in other words, the information that travels from our eyes to our brain via our nerves. Dee’s case of agnosia clearly suggests that in our brains two separate processes of visual information analysis are at work: the first supports the coordination of movement and is independent of the second which creates an inner image of the outside world. In Dee’s case the poisoning accident damaged the second mechanism, while the first continued to function normally.

The theory of two modules for processing visual perception in the brain has been developed by two British neurologists, Melvyn A. Goodale and A. David Milner, and presented in their book Sight Unseen: An Exploration of Conscious and Unconscious Vision (Oxford University Press, 2004). In it they also give a detailed description of the case of Dee Fletcher who they examined and tested on several occasions following her accident. In the book, they also present cases of patients with the inverse combination of symptoms of those Dee has. It can also happen that the patient can recognize shapes, but cannot recognize colors. However, this is not a classic example of color blindness where the color receptors in the eye are damaged. These patients are capable of effortlessly passing the classic color blindness tests, because they can distinguish the borders between two different colors of the same intensity, which the typical monochromats cannot do, but they are still unable to tell which color they are seeing. When asked to draw a banana, for example, nothing would stop them from choosing a red or a green crayon instead of the yellow one.

Fifteen years after the accident the two scientists went to visit Dee and her husband Carlo in their home. They say that when Dee came to open the door, she showed almost no signs of blindness at all. She has no difficulties with moving through her home quickly, cooking and even working on the garden which she was also glad to show them. When they went for a short trip the following day she seemed to follow the forest path easily, and they only had to tell her which the right trail was occasionally.

Although she never regained perfect vision, Dee succeeded in making use of the sight mechanism which remained unharmed after the accident. She now tells people apart by the color of their clothes and the details in the structure of the surface that she can recognize. She uses the same technique when doing household chores which she now performs considerably better than immediately after the accident.

Is marriage a mathematical operation?

One autumn Sunday in 1934 the director of the prestigious Parisian school École Normale Supérieure (ENS) called up a young philosopher called Claude Lévi-Strauss and asked him if he was interested in applying for the position of Professor of Sociology at the University of Sao Paolo in Brazil. Lévi-Strauss who had not yet reached his thirties accepted the offer to leave for this faraway place mainly because he wished to distance himself mentally from the European intellectual scene. He thought it to be too involved in dealing with abstract problems and was more interested in immersing himself in anthropological field work.

A World on the Wane

Lévi-Strauss later remembered that the director of the ENS was, at the time he offered him the job in Sao Paolo, certain that the natives were already to be found in the suburbs of the Brazilian metropolis, and that the philosopher, interested in the relatively new discipline of gathering information about peoples of different cultures and their customs in the field, could study their culture during the weekends.

Naturally, there were no natives near the university where Lévi-Strauss spent the following couple of years lecturing. On several occasions, however, he did set off for the more remote places in the rainforest where he could learn about the customs and the way of life of the Indian tribes. Even though he spent a lot of time in the field and is today believed to be one of the principal names of anthropology and philosophy of the 20^th century, he was neither a classical field anthropologist nor a classical philosopher who almost never leaves his desk.

In fact, he was interested in solid data describing the customs of specific cultures and wanted to use the gathered information to reveal the universal structure, characteristic not only of a certain tribe, but of all human societies. He later described his expeditions to the Amazon region in detail in his book entitled A World on a Wane, which combines his autobiographical notes with an analysis of the lives of Indian tribes.

Are you the guy who makes jeans?

On his return from Brazil he quickly realized that the situation in Europe was even worse than when he had left for South America. The air was thick with the anticipation of the Second World War, and because he was of Jewish origins, he only thought it wise to leave France once again. He decided to accept the invitation of the renowned private school The New School for Social Research in New York which offered him tenure.

Immediately after his arrival to the US, his acquaintances kindly suggested that he change his name as soon as possible. If he refused to do so, anyone who met him would think that he sold jeans. Even though it all seemed to be a joke at first, he quickly came to realize that the similarity of his name to that of the famous jeans manufacturer was more of a nuisance than an entertaining coincidence. In order to avoid unwanted misunderstandings he decided to sign his name Claude L. Strauss during his stay in the US. However, this change was not effective enough to save him from receiving orders for the legendary blue jeans to his address every once in a while.

The French in Manhattan

In New York, Lévi-Strauss made the acquaintance of the Russian linguist Roman Jakobson who also lectured at The New School. They quickly discovered they had very similar approaches to science. Lévi-Strauss tried to introduce the method that Jakobson had been developing in the field of linguistics to anthropology. In order to become familiar with each other’s past research they also frequented each other’s lectures.

Many other French intellectuals spent the wartime years in New York as well. During the week, Lévi-Strauss spent his time with Jakobson, immersed in problems concerning anthropology and linguistics, while on weekends he joined the painter Max Ernst and the writer André Breton to look for Native American art in the local markets.

The Elementary Structures of Kinship

Jakobson was very impressed with Lévi-Strauss’s doctoral thesis so he encouraged him to publish it in book form as well. In his thesis, Lévi-Strauss examined the structures of family relations in different cultures around the world. Each culture has its own specific rules determining who can marry whom, and determines which newly created family bonds are strictly forbidden.

The Elementary Structures of Kinship, as the book was called when it was finally released after the end of the Second World War, is still considered to be one of the most important works in the field of anthropology. It also had a great influence on other fields of science.

When Lévi-Strauss was preparing his manuscript for publishing in New York, however, he realized that he was still missing the essential part. He had plenty of data which he had gathered in the field, but he wanted to arrange it into a coherent whole, ant this is were he stumbled upon an obstacle. While using the same approaches that Jakobson had been applying to linguistics, he failed to find the inner logic within his field data on the acceptable and prohibited ways of creating new family relations.

As he knew that finding a structure within data was also a mathematical problem, he turned to his mathematician colleagues, but they were not of much help. One of the representatives of the older generation even advised him to stop looking for principles because he would not find any: “Mathematics only knows four operations and marriage isn’t one of them.”

A mathematician comes to the rescue

After a while, he finally managed to find his luck. In New York, he met a young French mathematician André Weil who also gave lectures at one of the American universities. Weil was a mathematician of a new variety who did not have much in common with his elderly colleagues. He was one of the principal founders of a group of young French mathematicians who published their scientific discussions and university textbooks under the collective pseudonym Nicolas Bourbaki.

Their basic principle was to set mathematics onto new foundations, mostly with the aid of set theory. In fact, The Bourbaki group was responsible for the famous new mathematics reform, moving the focus from arithmetic to sets and operations involving sets.

In his research, Lévi-Strauss gathered a large quantity of data on family relations in different cultures of the world. He found out, for example, that similarities exist even between family structures of groups living as far apart as the Indian tribes of Brazil and the Aborigines of Australia. However, he could not succeed in revealing the general structure or system of all the acceptable newly formed family bonds.

“When in doubt, look for groups!”

After Lévi-Strauss explained his problem to André Weil, he immediately suspected that the structure that could organize the mass of anthropological data into a coherent whole could be a mathematical group. This completely abstract algebraic structure, which was not as well known in the mathematical community then as it is today, turned out to be a structure that can also be found in most unlikely situations like marriages between the Australian natives.

Weil was well known for his motto: “When in doubt, look for groups!” And, in fact, this abstract algebraic approach was actually useful when applied to anthropology. The essential principle that Weil applied to Lévi-Strauss’s data was that he ignored the very elements among which he was supposed to seek out regularities. He did not focus on the types of marriages, but on the relations between weddings. The structure was not hidden in the marriages as such, but in the differences between types of marriages. This approach was in complete accordance with the ideas of the Bourbaki group that the relations and structures are the central elements of mathematics.

Weil found out that the structure of relations between the marriages of the members of different generations and tribes was defined by a permutation group. He described his findings in a discussion which was published as an appendix to Lévi-Strauss’s influential work. More than a concrete analysis of family relations, this book is important because of its influence, as it introduced the notion of structure as a system of differences, causing a veritable intellectual revolution.

The interdisciplinary cooperation of Lévi-Strauss, Jakobson and Weil in 1943 in New York became a thing of legend. Three leading experts on anthropology, linguistics and mathematics, each brilliant in their own field, so different at first glance that it is hard to imagine how they could talk about anything other than the weather, came together to achieve an amazing scientific breakthrough. According to science historians, that was when the structuralist movement, which influenced all social sciences, mathematics and philosophy in the second half of the 20^th century, came to life.