During the 1930s and ’40s, the Dutch forger Han van Meegeren made a fortune by successfully passing off many of his fakes as authentic paintings by Vermeer. There is nothing exceptional about this except that, looking at van Meegeren’s paintings now, his success seems incomprehensible. His forgeries look nothing at all like Vermeer’s work. How could it have happened that knowledgeable collectors and even experts were taken in by paintings that would be quickly spotted as fakes today?
In fact, this is not surprising if one understands how determinations of authenticity are made (aside from chemical analyses of pigments and other materials). What the expert does is to consider the entire known corpus of the artist’s work and decide whether the painting in question appropriately resembles those whose authenticity has already been confirmed. Van Meegeren’s plan was to find an expert whom he thought he could sway into authenticating one of his forgeries, and then to capitalize on the fact that one of his paintings had now entered the collection of allegedly authentic Vermeers, the very collection that served as the touchstone for adjudicating future additions to the collection.
The idea worked brilliantly, and indeed its success snowballed. With each new authentication, what was believed to be Vermeer’s corpus came to include more and more van Meegeren forgeries, which only increased the odds that the next forgery would be deemed authentic. After a while, it became impossible to sort out what was a real Vermeer and what a fake simply on the basis of comparisons with works believed to be by Vermeer.
What van Meegeren had truly mastered was the art of poisoning the wells. In the context of reasoning, the technique stems from the following fact: We do not assess whether a claim is reasonable simply by thinking about that claim in isolation. Usually, we relate the claim to a body of beliefs we already hold. Relative to that corpus of accepted beliefs, we decide whether the new claim is a reasonable one to make. Given this feature of reasoning, one sees how our very capacity to assess claims can be radically undermined if one poisons the body of beliefs relative to which we normally judge matters. If we don’t know which of our background beliefs to trust, then how can we appeal to them in deciding whether to believe a new claim? And since that is usually the only way of deciding these matters, such a poisoning of the wells of belief leaves us powerless to make any further decisions about what to believe.
Behind every great philosophical skeptic there lies a well poisoner. And there is no more bravura performance in the history of philosophy than René Descartes’s “Meditations on First Philosophy.” He begins by trying to show that none of his beliefs about the everyday world around him can be maintained. These include such obvious beliefs as that he has two hands, that there are other people moving around him, that mountains do not fly, and so on. How does he do this? He poisons the wells! What are the wells in this case, what is the source of our confidence in such beliefs?
Our confidence in these beliefs rests on our confidence that our sensory apparatus, our eyes and ears, delivers accurate information about the natural world. What Descartes proceeds to do is sow doubt about the reliability of our senses through a series of ingenious arguments, which includes famously raising the possibility that we are dreaming. He proceeds like the enemy army that sees the inefficiency in denying individual households access to the communal water supply and instead opts for the expedient of well poisoning, which in one fell swoop achieves the general goal. In fact, Descartes eventually does such a thorough job of poisoning the wells of belief that he is left with virtually nothing he can believe at all.
Descartes as it turns out is not himself a skeptic, and he spends the remainder of the “Meditations” trying to pull himself out of the skeptical hole he has dug for himself. He does so to his satisfaction. But it is fair to say that he did not convince most of his readers, and there is still a lively debate as to how, if at all, it is possible to regain one’s footing once the sources of rational belief have been radically called into question.
There is a lesson here about the lurking dangers of Donald Trump’s rhetoric and that of his minions. Citizens in a technologically advanced liberal democracy must rely on its scientific community to deliver disinterested information upon which to base their decisions about the policies they would have their elected representatives enact. Citizens are also highly dependent on a probing press to help them judge the performance of their elected representatives. Trump, first as a national candidate and now from the pulpit of the presidency, has not ceased to deny and denigrate the findings of scientific bodies concerning the rate and causes of climate change. In addition, he regularly calumnies individual members of the press and vilifies entire news organizations. They are dismissed as purveyors of “fake news” — a label Descartes’s skeptic might have been delighted to apply to the allegedly untrustworthy deliverances of our sense organs.
This behavior is not merely offensive and outrageous. The real problem is that it is dangerous: It poses an existential threat to our democracy. These attacks poison the wells of reasoned public discourse, a prerequisite for a functioning democracy. The problem is not merely that we are being fed a falsehood here, a lie there, though that would be problem enough. The issue is rather that by destroying the citizenry’s confidence in the institutions of science and the press, we risk being deprived of the tools needed to assess what to believe and want. If we cannot trust what vetted scientists or professional journalists tell us, then we will have been rendered rationally impotent. It is damaging to be fed falsehoods or to be outright lied to, but it is utterly debilitating to be deprived of the resources by which to sort fact from fiction.
Descartes’s skeptic is a traitor to knowledge: His threats are not directed piecemeal but instead to the entire enterprise of coming to know how things are. The assaults on science and the press by Trump and his followers are not local eruptions of deceit and mendacity but a well-poisoning assault on public rational discourse, a prerequisite for a healthy democracy.