What we talk about when we talk about post-truth

As I write this and as you read it, and indeed for several million years into the future, there will be a dummy named Starman in a red Tesla cruising through outer space, playing an infinite loop of David Bowie’s Space Oddity. This achievement of SpaceX’s Falcon Heavy rocket carries multiple meanings, but one of them, enthusiastically driven home on Twitter, is that the livestreamed pictures of Starman set against the Earth’s sphere would finally put an end to Flat Earth theories, whose proponents often cite as proof the absence of a clearly distinguishable curve in photographs of the Earth.

For their part, the Flat Earthers, like anti-vaxxers and Pizzagate-believers among other crusaders in our post-truth world, remained unshaken. They cautioned Flat and Round Earthers alike against uncritically trusting all the information shared on the internet via fake-news websites, and asked people to exercise greater critical judgment regarding the sources of online content – in this case, a private company guided by a quest for profit, not truth. They claimed that to use ‘a good car ad’ to establish so crucial a matter as the Earth’s shape is simply ‘a poor argument’. Committed to seeing our planet as a floating two-dimensional circle, they appealed precisely to objectivity, critical judgment and the quest for truth.

Anti-vaxxers who refuse to vaccinate their children due to autism fears tend to care far more about what risks vaccination might carry than, say, a childless scientist might. Few (if any) liberals drove five hours to Washington, DC to check the ‘objective’ facts of Pizzagate – unlike Edgar Maddison Welch, who in 2016 fired shots at the restaurant allegedly at the centre of a paedophile ring run by Hillary Clinton’s campaign manager. Objective facts and sound verification procedures are not what post-truth groups deplore but, specifically, what drives their dissent. What post-truth groups do deplore are established facts and agreed-upon truths. The issue is one of trust, not verification.

In The Web of Belief (1970), W V Quine and J S Ullian argued that what makes scientific statements true is not their faithful correspondence to external facts, but their internal coherence and the persuasive narrative they jointly form. Our beliefs face the tribunal of experience not one by one, with each matched to facts that directly confirm or disprove it, but as a layered body or web that interacts with observable facts only at its margins.

Whenever a fact contradicts one of our beliefs, we are prompted to restore consistency by revising some of the beliefs in our web. But in choosing what to revise, we are no longer guided by facts alone. Starting from the anomalous evidence, we look at the contested belief and its supporting justification(s), and assess how consistency can be most parsimoniously restored in light of the full web of our beliefs. We can end up revising anything, from doubting that we actually observed the anomalous evidence in the first place, to the principles of logic and mathematics that lie at the centre of our web.

According to the crowdfunded campaign ‘Show BoB The Curve’, a photograph of a city that remains visible at a great distance, instead of being hidden under the horizon, contradicts the belief that the Earth is round. To solve this tension, we can either dismiss the observation as irrelevant given our firmer beliefs in established astronomy and geology, or else question the scientific consensus, based on satellite images and the testimony of astronauts. The first option is less disruptive to our web of belief, but demands that we discount direct empirical observation. The second option – taken by Flat Earthers – vindicates the direct observation but requires that we reject every theory, experiment and observation pointing to a round Earth. The difference is in the epistemic authorities that one trusts, not in the relevance of facts for establishing truth.

This centrality of trust holds, moreover, for scientists themselves, whose observations rely on trusting in the theories and experiments of colleagues and previous researchers; trusting one’s measuring and interpretative equipment; trusting in the textbooks and lecture materials from where one has learned the fundamentals of a given discipline, etc. Even ‘so-called’ direct observations, writes the British sociologist of science Harry Collins in Gravity’s Shadow (2004), are but ‘tiny corks bobbing on a huge sea of trust’. For Flat Earthers, distrusting the scientific consensus entails replicating evidence that has been at humanity’s disposal since the 1600s, hoping that, through using crowdfunded weather balloons, they will find the opposite answer.

Such wholesale revisionism underscores the social and political impact of post-truth, as well as the false symmetries created by claiming that your detractors are guilty of the very thing of which they accuse you. On the model of Quine and Ullian, such contradictions challenge accepted beliefs across our web, requiring us to choose which authority to trust to restore consistency. In the case of Donald Trump’s inauguration crowds, believing official statements about attendance figures meant distrusting photographic evidence shown across ‘the liberal media’. The disbelief was not isolated to the peripheral observation of a single photograph, but ran through the whole web of belief, challenging all information from this polluted source. Whatever the political gamble, the result is an escalation of epistemic commitment across social divides, creating the impression that the other side is not only in the grip of a false authority, but inhabits a separate reality.

There’s nothing new in relying on authority for establishing truths. But insofar as post-truth is a new reality rather than an old but now more visible one, its novelty resides in distrusting established guarantors of truth, in part simply because they are established, while trusting grassroots observations over the venerable edifice of science. While the appearance is one of subjectivity, it is driven, paradoxically, by a search for objectivity. For this reason, fact-checking cannot combat post-truth, since it’s based on the fundamental misconception that those in the grip of spurious epistemic authorities roughly share the same belief set as us. We need to recognise the fact that when authorities change, the world changes, and the differences are not isolated facts that can be easily weeded out. Invoking images of Starman to refute Flat Earth theory acts as if knowledge proceeded unproblematically from observation reports to theory. Instead, as Collins puts it in Gravity’s Shadow, ‘the causal sequence runs the other way: not from stars to human apprehension, but from human agreement to the stars’.