Introduction
Problematization

Problematization does not mean the representation of a pre-existing object, nor the creation by discourse of an object that does not exist. It is the set of discursive or non-discursive practices that introduces something into the play of true and false and constitutes it as an object for thought.

Michel Foucault, "The concern for truth," 1988

Public health erupted into the world's consciousness early in 2020. In the case of France, the moment can even be precisely dated: 17 March, the first day when the majority of the population was confined to their homes. For what is unique about the Covid1 epidemic is not the nature of the infection, which is of course serious, though less contagious than measles and not as lethal as AIDS, but the way societies reacted to its emergence. The pandemic, and the responses to it on every continent, generated a worldwide upheaval in human activity. In many other countries, lockdown was an experience without precedent, apart from its echoes of some aspects of the response to outbreaks of plague in the late Middle Ages and cholera in the early nineteenth century. Health policing, with its arsenal of prohibitions, requirements, checks, and sanctions, was the most widespread manifestation of public health, even once people began to be vaccinated. But it took many other forms: social distancing, the wearing of masks, the practice of testing, the isolation of patients, the tracing of contacts, the recurrent and swiftly refuted announcement of treatments, fierce and often unequal competition in the search for a vaccine, daily public counts of cases and deaths, intrusive and ineffective surveillance measures, not to mention the exceptional provision for both economic and social support aimed at preventing business failures, limiting lay-offs and mitigating the consequences of the abrupt destitution of many families. The implementation of these policies was accompanied by hesitations and reversals, debates and controversies, martial declarations and contradictory assertions, flagrant lies and lethal obstructions. In much of the world, everything that keeps societies in motion suddenly began to revolve around questions of health. Public health, which for many until then had been no more than an abstraction, an obscure administrative matter, a rather unappealing field of expertise, became the principle for the government of lives - a "government of living beings," as Foucault puts it.2 His phrase should, however, be taken literally - more so than he himself does - considering it as the government of human beings inasmuch as they are living beings who must, "at all costs," as the French president articulated it, remain alive.

It so happened that, a few months before the first cases of Covid were diagnosed, I was elected to the Annual Chair in Public Health at the Collège de France. My course was due to begin on 29 April, six weeks after lockdown was imposed. It was therefore postponed and took place a year later, albeit in almost identical conditions owing to both a new wave of the epidemic despite the beginning of vaccination, and a renewed, although less draconian, lockdown. For, contrary to the hopes of many and the predictions of some, the infection still loomed in the present. In the interval, however, my course had gained a new significance. Its subject, public health, hitherto barely recognized, had become the central topic of conversation and concern, insinuating itself into the everyday lives of each and every one, and equally into national politics and international relations. But it raised the question of how to tackle this topic that had suddenly invaded both public and private space to the extent that it absorbed almost all the attention of the media, politicians and citizens. Should I refocus my analysis purely around the pandemic, which lent itself to an anthropological reading on many levels, but would mean letting go of the richness of this multifaceted, diverse field? Such an approach risked giving in to the lure of presentism, forgetting that public health has a long history that could inform present anxieties. It would also mean consenting to a form of ethnocentrism, losing sight of the fact that many societies were struggling with other, more serious health issues. I therefore decided to take an alternative approach. I started from a banal and little-known scene illustrating various aspects of public health which I analyzed through a number of case studies over the course of the lectures, and I ultimately showed how each of these aspects sheds a different light on the Covid pandemic.

The scene in question is the emergence in France of the epidemic of childhood lead poisoning in the late 1980s. It can be considered both in terms of social production, the result of harsher immigration policies and a slowdown in housing policy, and in terms of social construction, through the fumbling, digressions and resistances of the actors involved. As a linking thread through the lectures, this investigation enables me to explore some seemingly unusual but nevertheless fundamental dimensions of public health: the power of positivism, the boundaries of disease, conspiracy theories, morality tests, and finally the challenges posed by the health of migrants and prisoners. The exploration transports readers from France, which has the highest level of prison suicides in Europe, to South Africa, the country that has been the worst affected worldwide by the AIDS epidemic, and Ecuador, which announced that it had the highest official maternal mortality rate in Latin America; from the scientific controversies of the "worm wars" in Kenya to confrontations between physicians and patients around Gulf War syndrome in the USA; from exotic pathologies at the Institut Pasteur to colonial psychiatry at the École d'Alger; from the origins of psychic trauma in World War I to the enumeration of deaths during the 2003 heatwave in France. The journey ends with an examination of the Covid pandemic in light of each of the dimensions explored in the preceding lectures in order to propose a new reading of it - revisiting it from an anthropological point of view.

Anthropology, as I understand it, is a way of looking at the world otherwise, of reflecting, like Ulrich, Robert Musil's "man without qualities," that "it might just as well have turned out differently."3 It is an exercise in intellectual dishabituation. In order to accomplish this, it can draw on more than a century of research by anthropologists who have explored multiple facets of human activities and relations in diverse places around the world, from the Nuer of South Sudan to the Nambikwara of Brazil, as well as among various groups in their own societies, from the anti-witches of the Mayenne Bocage region in western France to the Canadian experts in Alzheimer's disease, and have thus learned that everything that seems self-evident in one context may appear completely differently in others.4 But this cultural relativism does not lead them to become hunters of the exotic: quite the opposite. As Jean Bazin emphasizes, when faced with alterity they strive to reduce it by familiarizing themselves with the social worlds in which they conduct their research, whether geographically remote or close to home.5 This practice helps to make intelligible phenomena that experts have defined as imaginary, such as chronic Lyme disease, by showing that they result from the impossible confrontation between the authenticity of patients' suffering and the authority of doctors' knowledge. It also contributes to the explanation of phenomena that arouse anger or derision, such as paranoid beliefs around AIDS, which can be shown to have a heuristic value as they provide clues to interpret lines of cognitive fracture in contemporary societies. But it also leads the anthropologists to defamiliarize themselves with their own social world, making what is taken for granted less self-evident. For example, it can prompt them to wonder about the belief in the single, neutral truth of numbers in describing health, when the validity of randomized trials is contested or when disputes arise around the interpretation of mortality statistics, or to question the existence of a separate field of migrant health, as if exiles presented specific pathologies when in fact their poor health is a product of the way they are treated by the so-called host society. Thus, the anthropologists know, through their own experience and from that of those who have preceded them, that there are many ways of being in the world, and that the one that has long seemed the only right way is not necessarily more right than others.

It is such a shift of gaze with regard to public health that I have proposed in this book. Hence the subtitle "anthropological excursions." An excursion, the dictionary tells us, is "the action of traversing a region to explore or visit it." The word, which first appeared in both English and French during the sixteenth century but only became common much later, derives from the Latin excursio, meaning "journey," "incursion," and, in the figurative sense, "ramble" or "digression."6 This idea of exploration, freedom, and adventurous investigation points to the method of my inquiry. It explains my frequent preference for a narrative form, after the manner of what could be the tale recounted by a traveler in the "worlds of public health."7 Here I speak of worlds not in the sense of...