One lesson of Ludwig Wittgenstein’s final work On Certainty is that responsible inquiry on a topic requires that we take certain things on trust rather that seeking evidence in their favour: inquiry which is open to investigating absolutely everything is unlikely to make much (if any) progress on what we originally intended to find out. However, accepting things without evidence is also one important hallmark of prejudiced thinking.
How can we tell the difference between cases in which accepting something without evidence is an aspect of being a responsible inquirer and those in which it is mere prejudice and must be avoided? This question is all the more urgent in our current social and political milieu, where many significant social harms are caused by people prejudicially accepting things they ought to investigate, due to the influence of fake-news, conspiracy theories, propaganda, echo chambers, and other such phenomena.
Wittgenstein’s posthumously published final notes On Certainty (Wittgenstein 1969) teach that it cannot be true in every case that suspension of belief should rationally be the default stance from which one should move only when presented with cogent evidence to do so. It’s in the very nature of inquiry that sometimes it has to be rationally permissible to have an opinion before confronting any evidence (Wright 2004). One often invests trust in one’s eyesight and other senses, in the instruments one uses to take measurements, and in the sincerity of one’s interlocuters without having evidence that speaks in their favour. Of course, sometimes their trustworthiness is called into question, in which case one will need to investigate before relying on them again, but these investigations are further inquiries which in turn will make certain assumptions which one lacks evidence for; clearly, however, this chain of investigations can’t continue indefinitely. Inquiry has to take some things for granted, or it will never get started at all.
Wittgenstein’s reasoning demonstrated that the demand that one has evidence for everything one accepts is not an ideal that a responsible epistemic agent ― a responsible believer and inquirer ― can aspire to. On the contrary, being an epistemically responsible agent requires that one takes some things on trust, without evidence.
On the other hand, unevidenced opinion in inappropriate cases is exactly what prejudice consists in. How is this distinction between cases in which accepting something without evidence is demanded of us as responsible epistemic agents and those in which it must be avoided to be drawn? How are we to recognise on which side of this distinction particular things we accept fall in practice (if this is even possible at all)? What steps might we take as an epistemic community to promote responsible inquiry, given the risks of falling into prejudicial thinking? These questions have particular urgency in the present social context, in which real social harm is being caused both by unjustified doubts ― climate change denial, vaccine scepticism, distrust of experts generally ― and unjustified acceptances ― the phenomenon of online echo chambers, the prevalence of so-called “influencers”, the proliferation of conspiracy theories and propaganda (Lackey and McGlynn 2025).
The distinction to be explained thus provides an example where philosophical research can promise results of genuine societal importance. Not that we should expect direct social benefit from philosophical progress on these matters. But improving our understanding of when credulity and scepticism respectively are rationally justified and intellectually responsible may be an essential step to helping those ― for example, teachers and policy makers ―consider how best to implement relevant social and educational changes.
The broad aim of the Responsible Trusting Without Prejudice project as outlined above will require engaging in depth with a number of more specific research problems.
First, there is the question of clarifying the limits of certain kinds of rationally unavoidable epistemic trust. The issues here will involve extensive scholarship of Wittgenstein’s last writings, published as On Certainty, as well as a thoroughgoing review of recent literature in the growing field of so-called ‘hinge epistemology’. We will seek to develop a comprehensive taxonomy of presuppositions that enquiring rational agents cannot but “take for granted” as background to the responsible formation of belief—presuppositions, for example, about the effectiveness of their own cognitive capacities and the suitability of the circumstances in which they are deployed for the effective function of those capacities. Some (not all) of these presuppositions will admit of independent investigation, but that of course will rest upon a further set of presuppositions.
Second, we will need to give direct theoretical attention to questions concerning the nature of epistemic responsibility itself. Clearly, we are not responsible for our beliefs in the same way as for our freely chosen actions. But we do hold people responsible for prejudice, for ignoring evidence, for carelessness in investigation, and so on. We will seek to clarify to what extent we are genuine epistemic agents who can justifiably be held responsible for what we believe, and what may be the limits of such agency.
Third, a review will be required of issues in the epistemology of testimony, broadly construed: to what extent, about what topics, and under what conditions, is it reasonable to take testimony, or external information-sources generally, as reliable without specific evidence to that effect? What are the presuppositions of so doing? There are special difficulties with expert testimony here, since the reliability of experts is, for most of us, something on which our only ultimate evidence will be itself the testimony of experts. These enquiries will underwrite our research on a crucially important question: to what extent and by what means can a responsible epistemic agent mitigate the effects of a social climate in which (to a significant degree, deliberate) misinformation is rife?
We are living through the “post-truth” or “disinformation” age, in which everyone from politicians to advertisers continually lies to us, large corporations control what we see online via opaque algorithms, and generative AI makes it ever harder to trust what we see and read. Relatedly, people’s political views are increasingly polarised, to the point that it seems like we can’t agree on the most basic facts, or even on the best methods for reaching the truth.
The project will clarify what it takes to be a responsible inquirer in a world that is so uncooperative, and where the consequences of lapsing into prejudicial thinking are so harmful.
The most effective strategies for avoiding prejudice as individuals and as communities can only be determined by careful empirical study, but a philosophical account of responsible epistemic agency can contribute to our understanding of what these strategies are aiming to accomplish.