To believe what philosophers say about their field, you might be forgiven for thinking that they are seekers after the truth. However, as in so many other cases, you shouldn’t believe the hype. On the contrary, philosophers are the ultimate experts in a post-truth world. They see ‘truth’ for what it is: the name of a brand ever in search of a product which everyone is compelled to buy. This helps to explain why philosophers are most confident appealing to the truth when they are trying to persuade non-philosophers, be they in courtrooms or classrooms.
Anyone who finds my judgement too harsh or cynical is invited to consider the careers of the key philosophical terms in which knowledge claims are transacted, not least ‘evidence’ and ‘truth’ itself. ‘Evidence’ is a good place to start because it feeds directly into the popular image of our post-truth world as ‘post-fact’, understood as a wilful denial of solid, if not incontrovertible, pieces of evidence, whose independent standing sets limits on what can be justifiably asserted about the world.
It was only in the early modern period that philosophers even began to distinguish a purely fact-based conception of evidence from personal revelation and authoritative testimony. The break only became clean in the mid-nineteenth century when logic books regularly started to classify people-based claims to evidence among the ‘informal fallacies’.
This slow crafting of the concept of evidence was part of the general secularisation of knowledge. But it would be a mistake to think that today’s concept was purpose-made for scientific inquiry. Rather, it was an adaptation of the inquisition – the procedure used on the European continent to identify heretics and witches. Its English importer was Francis Bacon, King James I’s lawyer, who believed that nature itself was a fugitive from the law, hiding its secrets from humanity for much too long. Special trials were thus required to force nature from its normally equivocal stance to decide between two mutually exclusive options.
Bacon called such trials ‘crucial experiments’, which Karl Popper turned into the gold standard of the scientific method. But Bacon and Popper were under no illusions that the facts produced under such ‘extraordinary rendition’, as we would now say, were nature’s deliverances in more relaxed settings. Popper went so far as to call facts ‘conventions’, by which he meant convenient waystations in a never-ending inquisition of nature. After all, what made experiments ‘crucial’ was that their outcomes hastened knowledge of a future that otherwise would only unfold – for good or ill – on nature’s timetable, which would provide humanity little opportunity to plan a response.
As for ‘truth’, it harks back to an older English word, ‘troth’, which harbours all its philosophical difficulties. ‘Troth’ means faithfulness – but to what exactly: the source or the target? Originally truth was about loyalty to whomever empowers the truth-teller, be it God or a general. In this context, it was associated with executing a plan of action, be it in the cosmos or on the battlefield. One remained ‘true’ by following through on the power-giver’s intention, regardless of manner or outcome. It’s this sense of ‘true’ that enabled the Jesuits, a Catholic order founded by a soldier, to do God’s work by operating on the principle that ‘the ends justifies the means’.
However, it was thanks to another Catholic, Thomas Aquinas, that truth came to be seen as loyalty to the objects already in the field of play. His own Latin turn of phrase was adequatio ad rem, whose crude English translation, ‘adequacy to the thing’, captures the disempowering character of the concept, which philosophers continue to dignify as the ‘correspondence theory of truth’. Aquinas, writing at a time of considerable heresy, was nevertheless confident that the world as it normally appears is close enough to God’s plan that the faithful should stop second-guessing God’s intentions and focus instead on getting the empirical details of Creation right.
"Truth is the name of a brand ever in search of a product which everyone is compelled to buy"
These contrary pulls on the concept of truth have persisted to this day. When Newton famously declared ‘Hypotheses non fingo’ (‘I feign no hypotheses’) in the second edition of Principia Mathematica, he was diverting suspicious religious readers who feared that he might be trying to get into ‘The Mind of God’ rather than simply providing a perspicuous account of nature’s order. But of course, Newton was aiming to second-guess the God in which he believed. The funny thing is that avowedly ‘atheist’ physicists like Stephen Hawking, successor to Newton’s Cambridge chair, still aspire to do the same and differ only in the details of execution.
To see just how conflicted the concept of truth is in our times, one shouldn’t fixate on the ‘fake facts’ and ‘fake news’ easily associated with the Brexit campaign or Breitbart news. They are just the downstream effects of a much deeper division which the US philosopher Wilfrid Sellars canonized more than a half-century ago as the ‘manifest’ and ‘scientific’ images of the world – the two being understood as radically at odds with each other. Whenever someone tries to exert epistemic authority by saying that the truth is not as it seems, they are generally identifying with Sellars’ scientific image of the world. Of course, many paranoids say exactly that, and in the post-truth world the difference between the cranks and the deep thinkers lies in who can get the rest of the world to organize around their particular image.
One philosopher who offers guidance in navigating through the somewhat surreal post-truth intellectual environment is Hans Vaihinger, the leading Kant scholar from a century ago. He developed an entire world-view around Kant’s repeated use of the phrase ‘als ob’ (‘as if’). Much of the normative force of Kant’s philosophy comes from thinking or acting ‘as if’ certain things were true, even though you may never be able to prove them and they may even turn out to be false. Vaihinger called the resulting world-view ‘fictionalism’ and it epitomizes the post-truth sensibility. And seen through Vaihinger’s eyes, philosophy appears to be the most post-truth field of them all.
Contemporary philosophy is notoriously divided into ‘analytic’ and ‘continental’ schools. The analytics accuse the continentals of having picked up all of Nietzsche’s worst habits. The result is a trail of spurious reasoning, fake philologies, eccentric histories, obscurantism and hyperbole. This is quite a list of offences to the truth, yet it is striking that analytic philosophy’s most lasting contributions in the last half-century has been a series of thought experiments, which are no more than figments of the imagination that are passed off as heroic abstractions from some hypothetical reality. The rest of analytic philosophy is basically just scholastic wrangling about the wording of these thought experiments and the conclusions one is licensed to draw from them, leavened by occasional moments of high dudgeon, as well as displays of ignorance, narrow-mindedness and bias.
Vaihinger could make sense of what is going on here. He divided our approach to the world into fictions and hypotheses. In a fiction, you don’t know that you inhabit a false world, whereas in a hypothesis you know that you don’t inhabit a false world. In either case, ‘the true world’ doesn’t have any epistemic standing. From this standpoint, continental philosophers are purveyors of fictions, and analytic philosophers of hypotheses. What we colloquially call ‘reality’ moves between these two poles, never really honing in on any robust sense of truth. Here one needs to think of ‘fictions’ on a sliding scale from novels to plays to laws (‘legal fictions’) and ‘hypotheses’ on a sliding scale from what Euclid was talking about to what scientists test in a lab to what people do when they plan for the future.
Does this mean that truth is a redundant concept altogether? That there is a ‘redundancy theory of truth’, proposed by the logician Frank Ramsey nearly a hundred years ago, suggests as much. Moreover, the theories of truth that have followed in its wake – alternatively called ‘deflationary’, ‘disquotational’, ‘expressive’ and even ‘honorific’ – can be added to the post-truth, if not anti-truth, repertoire of at least analytic philosophy. But ‘in fact’ (assuming such a locution is permitted), Vaihinger would say – and here I would agree with him – that truth turns out to be whatever is decided by the empowered judge in the case at hand. In other words, Francis Bacon was right, after all, which perhaps explains why Kant dedicated the Critique of Pure Reason to him.