Smells. Robert Muchembled
team at Rockefeller University in New York claimed that humans are capable of discriminating over a trillion smells.1 Did the nose’s spectacular rise from also-ran to top dog, the sharpest of all the senses, prove the point of those who argue this is an age of dazzling progress? Alas, like the fleeting beauty of Ronsard’s poetic rose, the fabulous discovery soon lost its bloom. Two articles published soon after pitilessly skewered the flawed mathematical model used to scale up the team’s experiments on twenty-six volunteers.2 It could almost have been the episode of The Big Bang Theory in which Sheldon Cooper is thrilled when Stephen Hawking compliments him on his brilliant demonstration of a new theory, then crestfallen on hearing a moment later that the only problem is an error in arithmetic on page 2.
This is all very confusing for the historian. The science goes right over his head; he cannot work out which side is right and can only wonder what can justify such diametrically opposing views. After all, aren’t the critics of the ‘soft’ humanities always banging the drum of ‘hard’ science and its objectivity?
Experimental research on the human sense of smell has been gaining ground for some twenty-five years. The discovery of nearly four hundred olfactory receptors in humans has led to limited progress in molecular biology and physiology but has proved of major interest to neurobiologists.3 Scientists seeking to understand how cells recognize specific signals consider our sense of smell as an ideal subject for study because of the number and diversity of receptors. Furthermore, every individual has a practically unique set of olfactory receptor genes, creating a sort of personal ‘noseprint’ linked to our immune system, among other things.4
Yet it would be naive to think that science is driven solely by disinterested curiosity. The recent surge of interest in the human sense of smell is part of a vast cultural phenomenon whose underlying causes are deep-rooted, yet readily identifiable. You just have to follow the money. First and foremost are perfume companies, which come up with thousands of new products; in recent decades they have inclined to natural scents, which were considered beyond the pale until about 1990 by detractors of bad smells both physical and moral.5 Such companies, eager for information, are commissioning ever more studies. Other major sectors of the modern economy are also on the hunt for information – those that pollute our planet and their opposite numbers, the hygiene and health sectors, not to mention the vast food flavouring industry. Considerable amounts of money are at stake. Many promising young scientists are turning to potentially lucrative research projects in a highly profitable, fast-developing market. Some are hard at work identifying human pheromones. These are chemical substances supposed to attract the opposite sex: their very existence is questioned by some experts, though one 2009 experiment did conduct tests that suggested the existence of ‘putative human pheromones’, secreted by the glands of Montgomery in the breasts of lactating women. The as yet unidentified volatile compounds are thought to play a vital role in helping the newborn infant learn to suckle and in developing the bond between the mother and her baby.6
The food industry also greedily latches onto discoveries that align with its own interests. Teams of taste scientists work hard on studies such as the aforementioned project on the ‘smellscape’ of lactating women’s areolas, conducted at Dijon University Hospital. The stakes are high indeed, as, unlike the perfume market, this has every man, woman and child on the planet as a potential customer. Our fate is in the hands of laboratories that decide what is, or is not, good for us. For example, in 2008, the European Union took the precaution of banning a number of ingredients added to foodstuffs to give them a particular aroma (i.e. taste and/or smell) or to modify their own natural aroma. The list includes various flavourings naturally present in foodstuffs, found in plants such as chilli peppers, cinnamon, tarragon, St John’s wort, mint, nutmeg and sage.7
In this context, it is easy to understand why there is so much competition among research teams to come up with new data on smells, tastes and flavours, covering the whole range of sensations detected by our mouths. Even though the claim that humans can detect one trillion smells has been debunked, the article is still regularly quoted, commented on and referenced in popular science material, unlike the two articles that pointed out the flaws in the claim.
My own intuitive, highly subjective reading of all this is that science without consciousness of the past is but the ruin of the soul. At the very least, the recent deluge of studies on smell points to a new interest in a sense that is often underrated and underestimated. While the major causes of this spectacular shift may be the market economy and the drive for maximum profit, they have at least brought the nose to the fore after several centuries of neglect. When I first began researching the topic in the early 1990s, I asked a particularly promising student to join me in the project,8 but I eventually had to drop the idea for a full-length book because no publishers showed any interest. Things have changed, and now the time seems ripe for a historian to play his own little tune in the great orchestral concert of Smell Studies. Indeed, it has become a pressing necessity to prove that the humanities and human sciences are neither dead nor passé; rather, they are what give life its meaning in a world run by robots, a dictatorship of aloof multinationals where what matters is the bottom line. In 2015, the Japanese government requested the country’s eighty-six public universities to close their humanities and social sciences departments, or at least downsize and reduce enrolments, to focus on ‘more practical, vocational education that better anticipates the needs of society’. In September 2015, twenty-six of them complied.9 Despite a considerable public outcry, seventeen immediately stopped enrolments in the humanities and social sciences for the academic year 2015–16. The ministry proved it was playing the long game by staggering the reform over several years, until 2022. Other countries have carried out similar measures, albeit more discreetly, leading in the long term to a genuine threat to the culture of the humanities. I hope to demonstrate in this book that history and her sister disciplines are vital to our understanding of the modern world.
A sense of danger, emotions and delight
The human sense of smell is remarkable and unique. The team of scientists who first discovered the role of molecules produced by the areolas of lactating mothers concluded that their role was to help the individual, and therefore the species, to survive. This is true for all mammals. The widely held idea that the human sense of smell is weak and residual is merely a myth with no real basis: in fact, our sense of smell fell prey to cultural repression with the triumph of the bourgeoisie in the nineteenth and twentieth centuries.
While the fourth of Descartes’ Méditations métaphysiques ranked olfaction the third of all our senses, it was later scorned by philosophers and thinkers alike. Kant rejected it out of hand, considering it and its close relative taste to be the only subjective senses; Freud explained its supposed decline by ‘organic repression’, generated by the march of Western civilization. In around 1750, ‘aerist’ hygienists condemned smell for bringing people into contact with ‘putrid dangers’. Fast-paced urbanization in the industrial area saw smell become a major factor in class discrimination.10 The long period when our sense of smell was unloved and unsung is now coming to an end before our very eyes, and it is recovering some of the longlost glory the great historian Robert Mandrou intuited it must once have had. Way back in 1961, Mandrou argued that in the sixteenth century, when hearing and touch ranked higher than sight, people were ‘highly sensitive to smells and perfumes’ and delicious food. Ronsard’s poetry, for instance, associates kissing with the ‘sweet-smelling breath’ of his beloved.11
Our sense of smell has a number of highly original features. It develops in the foetus at twelve weeks. Learning about tastes and smells begins in the womb with amniotic fluid, which absorbs chemical traces of everything the mother eats. Some babies are born with a taste for garlic, for instance. It then takes another few years for the sense of smell to mature fully. The American experimental psychologist Rachel Herz is ‘convinced that our aroma preferences are all learned’, whereas the five basic tastes – salty, sweet, acid, bitter and umami (savoury) – are innate and therefore codify how we experience food and drink.12 My years of experience with American cuisine make me question her second argument somewhat, as the American love of combining sweet