We could focus on examples of post-truth, but that would not better prepare us to identify a new threat. Instead, we will highlight the process behind these examples, the skeleton of post-truth, its structure. That structure repeats itself, with slight variations, and if we manage to recognize it in new situations, we will have a better chance of fighting post-truth, surviving it and perhaps even exposing its creators. 

The first chapter of this section is dedicated to showing how the tobacco industry sowed doubts about the fact that smoking causes cancer. In the second, we will see something similar, but with the sugar industry, with the added complexity that it is something more recent, that we are still undergoing and that we do not yet know so clearly. Then, we will see that, although we know that climate change is occurring, caused to a large extent by human activity, society believes that there is more doubt than there is, partly because of the influence of the oil industry, one which would be most harmed by taking action to mitigate climate change. In these three cases, doubt is the product, and what is known is set aside.

Whoever properly controls information will have the post-truth factory. It is the Only Ring, the Ring to rule them all. Both doubt and unfounded certainty are transformed into products to be sold. Information is then manipulated, adulterated, and we, who operate on the basis of that information, do not know what to trust and what not to trust, and it all starts to look the same. 

Some may worry that this dissection of processes may end up helping the "enemy" by telling them what to do and what not to do, but there are two reasons to proceed: first, those who know how to handle post-truth already know these tricks, and there is nothing here that can help them; second, we could benefit greatly from being more aware of these tricks so that we don't get fooled or end up being unwitting promoters of post-truth. Let’s proceed.

Along the Silk Road, from Genoa to Cathay, through the deserts of Asia, caravans of traders and adventurers carried tea, silk and spices. Along the same route along which goods traveled, information also circulated: stories, ideas, technologies, worldviews. So much coming and going, and a palace dreamed of by a Chinese emperor appears in a poem written by an English poet under the influence of a Hindustani product.¹Kubla Khan by Samuel Taylor Coleridge. Not so surprising: information is a good like any other, something that has value and changes the world, and that is exchanged, bought and sold. A good that can be adulterated. 

Many changes in our world have to do with the availability of more and more information to more and more people. We are not going to discuss that good use, but about another one, when the tobacco industry sought to combat real data about the harm that cigarette smoking causes to human health by fabricating, hiding and generating information of dubious quality. 

According to data from the World Health Organization, tobacco kills some 7 million people every year, and causes cancer and chronic respiratory and cardiovascular diseases in many more. Tobacco is extremely toxic, and is the only substance that, used as intended, ends up killing half of its voluntary users. 

Of course, believing that tobacco causes lung cancer is different from proving it reliably. It was not at all easy to do so, not only because of the methodological difficulty in itself,[footnote content="See Hill, A. B. (1965). "The environment and disease: association or causation?", Proceedings of the Royal Society of Medicine, 58(5): 295-300." id="2"], but also because information was manipulated, in a process that today we would consider typical of post-truth. Even with all this against, finally the weight of the evidence was so great that today we can affirm with certainty that smoking tobacco causes cancer. 

The first clue was that when cigarette smoking became widespread in the early to mid-20th century, the incidence of lung cancer increased. Until then, it had been a very rare disease. 

This epidemiological evidence –which also showed a strong temporal relationship (the increase in cancer cases followed the increase in cigarette sales)-- aroused the strong suspicion that there was a causal relationship between the two, and not just a correlation. To study whether or not this was the case, evidence was sought using four different approaches. 

First of all, population-based, observational studies were carried out which clearly showed that the rate of lung cancer in smokers was much higher than in non-smokers, and higher in those who smoked more than in those who smoked less, indicating that the effect was dose-dependent. Moreover, this relationship was quite general and did not depend on location or personal characteristics. On the other hand, the increase in lung cancer cases was proportional to the increase in cigarette sales.³See Proctor, R. N. (2001). Tobacco and the global cancer epidemic, Nature Reviews Cancer, 1(1): 82-86. Many different observational studies, independent of each other, were carried out. In all cases, the correlation was very strong, but this alone is not sufficient to prove causality. 

Another line of evidence came from experiments with laboratory animals. An Argentinean, Angel Roffo, was one of the pioneers in these studies, and as early as 1931 he was able to demonstrate that concentrated smoke from tobacco distillation could cause skin tumors in rabbits. By 1950, there were already many other experiments in the world showing that tobacco smoke caused cancer in animals. 

A third line, beyond epidemiological observations or animal experiments, was cellular studies. Laboratory research was carried out on how cigarette components modified cells in culture (cells that are grown in glass plates and with which experiments can be carried out). In addition, cells from the respiratory tract and lungs of people who had died of lung cancer were studied in autopsies. The damage to the cells was clear. 

The fourth and final approach to search for evidence of the link between smoking and cancer was the chemical analysis of the components of cigarette smoke. Several carcinogenic substances were found. Again, Angel Roffo was the first to identify, in the 1930s, that cigarette smoke contains several types of compounds capable of causing cancer. 

Evidence obtained by different methodologies and approaches was piling up, and all of them pointed to the same thing: tobacco causes cancer.⁴See Proctor, R. N. (2013). Why ban the sale of cigarettes? The case for abolition, Tobacco Control, 22(11). This convergence or concordance of evidence is more than the sum of its parts: it is not a single approach that proves causality, but the confluence of all of them. 

Also, scientists began to look for any other factor, other than tobacco cigarettes, that could be causing the increase in lung cancer cases. But no other substances could be found: either the association between the two variables was not strong, or it did not conform to what was observed over time. There was no convincing and plausible alternative explanation to explain what was happening. Of course, a critic might say that such a hypothetical substance exists, we are just failing to find it. But we can't prove that something doesn't exist. When we add that to everything we do know about smoking, the causal association between smoking and cancer is strengthened. 

Evidence in hand, the health authorities then began to warn about the dangers of cigarettes and to carry out information and awareness campaigns. Along with this came the industry's counterattack, based on the creation of unreasonable doubt. 

One of the arguments against the idea that smoking causes cancer is that not everyone who smokes gets sick. But, in epidemiology, affirming that something causes something else does not mean that it will do so in all cases, but that it significantly increases the probability of its occurrence. Some even choose not to speak of cause in these situations, but rather that smoking is one factor, among many, that increases the risk of lung cancer. For our purposes, we will not go into these distinctions: we will speak of causality between two events, whether it is a direct and immediate relationship, or a more distant and indirect one. What is of interest to us in the case of a disease is to understand the risks in order to prevent them. 

Smoking greatly increases the risk of lung cancer. It's not that people who smoke get lung cancer. That would just be pure correlation. No, smokers who get lung cancer get it because they smoke. Even if not all smokers end up with cancer or not all lung cancer patients are smokers, to lower the risks of lung cancer, we can say with the highest confidence that the thing to do is to aim at prevention and not smoke tobacco. This is the causality that matters to us and the one we choose to highlight. 

As we see, proving causality is complex. As Jerome Cornfield said in a paper on this subject: "A universe in which cause and effect always have a one-to-one correspondence with each other would be easier to understand, but it obviously is not the kind we inhabit.".⁵Cornfield et al, (2009). International Journal of Epidemiology. 

In the 1950s, most physicians still did not accept the link between smoking and cancer, but the suspicion had begun to leave the realm of academia and reach the general public, especially when popular publications, such as Reader's Digest, began to cover the subject. This began to affect cigarette sales, which gave rise to resistance and possibly the first documented historical example of a large-scale, deliberate post-truth attack on modern science. 

In 1953, executives from six of America's largest companies met in Manhattan with John W. Hill, founder of a major public relations firm, to develop a joint strategy. At that meeting, a series of conscious and well-planned decisions were made that resulted in consumers, health care workers, journalists and government officials all doubting that cigarettes were killing people.⁶See Brandt, A. M. (2012). Inventing conflicts of interest: a history of tobacco industry tactics, American Journal of Public Health, 102(1): 63-71. Intentional, malicious post-truth was born: a series of actions aimed at generating doubts where there should be none. 

The tobacco companies, known collectively as Big Tobacco, decided to systematically attack the emerging scientific evidence, to advertise more aggressively - some of this is quite well represented in the Mad Men series –and to approach influential journalists to write in favor of cigarettes. For advertising, they often chose to show doctors who recommended smoking as being good for one’s health, or celebrities and opinion makers of the time. 

With respect to observational studies, the tobacco companies said that correlation does not imply causation, which is true. But they didn't mention that sometimes a correlation does show underlying causation: just because it doesn't imply it doesn't mean it doesn't exist. And with respect to the experiments, they said that what happened to animals was not comparable to what happened to humans. This is also true; of course, for ethical reasons, the only experiments carried out used rodents and similar animals, not people. But they chose not to emphasize that, while it is true that we cannot automatically extrapolate results obtained in animals to humans, the biology of laboratory mammals is not so different from ours, and that is precisely why they are so useful for research. They also suggested that, in reality, lung cancer –which they recognized was being seen more and more frequently-- could be caused by many other causes, and not necessarily by cigarettes. 

In other words, they used real aspects of scientific research, such as the fact that one can never be 100% sure of something and that more research can always be done on a subject, to distort the conclusions that were being obtained. It was like saying that since death is not 100% certain if you jump off a building, then we cannot say that jumping off a building is fatal.⁷And we discuss this in Chapter III. 

It is very easy to discredit what is already known by asking for more research, distrusting the results that are already available, casting doubt on solid knowledge. Asking for more science when science has already spoken is a strategy widely used as part of intentional post-truth: if something is already well known, skepticism is a very simple way to tear down what science has already elucidated. But, as we said, this is not being skeptical: it is being a denialist. And the tobacco industry was perhaps the first to adopt this strategy consistently.[footnote content=" See Ong, E. K. & Glantz, S. A. (2001). "Constructing 'sound science' and 'good epidemiology': tobacco, lawyers, and public relations firms," American Journal of Public Health, 91(11): 1749-1757. " id="8"] 

In parallel, Big Tobacco began to finance its own scientific studies to generate evidence in favor of cigarettes (starting from a basis as erroneous as commissioning studies to prove something instead of to test whether something is as we believe it to be). These investigations had, at the very least, methodological problems and, at the most, methodological constructions decidedly oriented to generate results which would benefit tobacco companies. All this was not too evident at the time, nor was it so striking that tobacco companies would fund tobacco research, something that today would be a clear conflict of interest that should be made explicit. These companies also financed research on many other topics, which positioned them in the eyes of society as "responsible companies" working for the common good. 

Big Tobacco's strategy was not to convince people that cigarettes were harmless. They did not seek to deny what was known, but to confuse the environment to generate a so-called controversy, doubt. That was enough to postpone regulations, taxes and accountability, and to keep cigarette sales high. It was the first time such a strategy was carried out. Before the word post-truth existed, Big Tobacco had generated a veritable instruction manual. 

Eventually, some journalists began to publish scientific information on tobacco in spite of the tobacco lobby. In the scientific environment, research financed by that industry started to be openly identified. Some time later came the first lawsuits against tobacco companies. 

A point worth emphasizing: If Big Tobacco's strategy was successful, it was also thanks to the fact that we, as a society, fell into its traps. First, we did not understand the science or seek scientific consensus, we confused competent experts with false experts, we did not notice that we received part of the information and not all of it, and that what we did receive was distorted by advertising and by the action of the tobacco lobby. In addition –and this is often the case with pleasurable and/or addictive substances or situations-- society, to a large extent, refused to accept the evidence that smoking was harmful. As cancer appears many years after taking up smoking, the causal association was not entirely intuitive, and the public disregarded scientific evidence. 

Some dates will help us understand how successful Big Tobacco's strategy was. By the 1960s, the causal relationship between smoking and cancer prevalence was already clear scientifically. This knowledge had already spread among health personnel and some officials. But until the end of the 20th century, the tobacco companies succeeded in managing public opinion, which for the most part continued to believe that there was a controversy when in fact there had not been one for decades. We will see this repeated in the examples we will mention later, along with another feature of intentional post-truth: by the time it reaches society, academic certainty is diluted.

It was only in 1994 that the tobacco companies were sued in the United States for the health damage they caused. In those trials, secret documents were revealed which showed that they knew perfectly well about the damage they were causing, but had concealed it. Even so, they put forward a defense strategy that may seem strange: they said that, since the harm caused by smoking was already public, the smoker was voluntarily assuming the risk. This was the first time Big Tobacco publicly acknowledged what was happening. And it wasn't that long ago. They went from "we are good for your health" to "there is no evidence that we are bad", and from there to "you knew we were bad and still chose to use us". 

Did it work? Yes and no:⁹ More on public policy on tobacco in Chapter XIV. although tobacco companies were forced to pay millions of dollars to the states and the federal Government and an important precedent was set, these measures practically did not affect the industry, possibly because they were moving the market to other countries. It is worth noting that cigarette taxes were further increased and advertising was regulated, and that not only was it revealed that they knew perfectly well that nicotine is addictive¹⁰In the movie The Insider, Jeffrey Wigand, played by Russell Crowe, is a witness who used to work for a tobacco company and divulges internal data in one of the trials. In the movie, he says that the company is in the nicotine delivery business and that cigarettes are the device that enables it. –in fact, they manipulated cigarettes so that more nicotine would reach smokers' lungs-- and that smoke inhalation generates innumerable health problems, but it also became very clear that there was a specific concealment strategy. An internal memo from 1969, belonging to one of the largest tobacco companies, explicitly stated: "Doubt is our product since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy." 

It is not difficult to generate doubt, and we should be aware of this because it is something that keeps happening. 

Once unreasonable doubt is sown, it is very difficult to correct it with facts. Of course, any valid criticism of the evidence and the conclusions drawn from it must be addressed and, if possible, answered. But valid is the operative word here. If the criticisms focus on irrelevant details, on poor quality evidence or on attempts to prove that something does not exist, we must ask ourselves, at the very least, whether there is good faith on the other side or whether, instead, there are attempts to delay the reaching of a consensus and the making of decisions based on it. Perhaps there is a lack of evidence on an issue, but perhaps there is evidence that some groups do not want to take into account because it conflicts with their previous position or their interests. If evidence is lacking, we must try to obtain it. In the latter scenario, the problem is something else, not the lack of science. This distinction is central to surviving post-truth. 

One thing is the more theoretical and abstract description of what information each type of evidence gives, and another is what happens with all that information in the real world, with the difficulties inherent in systems that are complex not only in relation to the scientific problems to be solved, but also with all the social, economic and value layers that are added.

When the tobacco companies' strategy –lying, hiding information, generating unjustified doubts, funding biased research to justify their point, etc.-- came to light, a new field of research emerged that addresses the questions of how they managed to mislead public opinion in this way, how they were able to manipulate it and create a false controversy. Robert N. Proctor, a historian of science long dedicated to studying these issues, invented the word agnotology in 1995 to refer to the study of the production of ignorance.¹¹See Proctor, R. N. and Schiebinger, L. (2008). Agnotology: The Making and Unmaking of Ignorance, Stanford, Stanford University Press. Agnotology is the study of actions taken to generate doubt, deception and confusion in order to obtain a benefit. 

It is not the ignorance of not knowing something that we could learn, nor the ignorance of putting aside knowledge that contradicts our previous positions, nor the ignorance of not learning something because it does not attract our attention. Agnotology studies culturally induced ignorance, that which is deliberately produced by someone on the basis of a given strategy. According to Proctor, agnotology is even more relevant today than when he proposed it, because "we live in the golden age of ignorance". And, just as we need to understand who and how they produce knowledge, we also need to understand who and how they produce ignorance. As we said, information is a commodity, and falsifying it, adulterating it or producing artificial scarcity can be good business for some. 

How can we, based on what happened with tobacco companies, better prepare ourselves to be able to identify similar situations in other fields? We present a new Pocket Survival Guide, one that is anchored on the previous ones, which helped us find the knowledge and allowed us to identify possible factors of unintentional post-truth. In this pocket guide, we will start from the assumption that we are talking about a factual subject, or at least one that has a factual aspect to it, and for which we want to find the truth. It will be a set of new suggestions to add to our toolbox, and we will take them up in the next two chapters. 

Talking about the generation of intentional post-truth by the tobacco companies is relatively simple in the sense that today it is very clear to us that cigarette smoking is very harmful to our health. It also helps that what the tobacco companies did in order to make governments and society believe that there was a controversy that in reality was not so is very well documented. Moreover, this has been known for several years now, so we have the advantage of being able to analyze the facts of the past more completely and from a distance. 

The following chapters deal with more complex situations, about which we do not yet know so much and whose problems are current. Let us begin with the sugar industry.