An epistemic alternative to the public justification requirement

How should the state justify its coercive rules? Public reason liberalism endorses a public justification requirement: Justifications offered for authoritative regulations must be acceptable to all members of the relevant public. However, as a criterion of legitimacy, the public justification requirement is epistemically unreliable: It prioritizes neither the exclusion of false beliefs nor the inclusion of true beliefs in justifications of political rules. This article presents an epistemic alternative to the public justification requirement. Employing epistemological theories of argumentation, we demonstrate how this approach enables assessing the epistemic quality of justifications of political rules, even when the truth is difficult to establish.


Introduction
How should the state justify its coercive rules?Public reason liberalism (PRL)a view predominant in contemporary political philosophyproposes a 'public justification requirement', according to which 'citizens must have sufficient reason to accept coercive laws if these laws are to treat persons as free, equal, and worthy of respect' (Vallier 2016, 349). 1 Thus, the public justification requirement serves to secure legitimacy for pluralistic societies by providing a standard that is internal, in the sense of being relative to the individuals constituting the public, rather than external, for example, grounded in facts or soundness (Wall 2002).Specifically, on 'the most common or mainstream' view (Vallier 2016), the public justification requirement upholds legitimacy if conditions of publicity and acceptability are satisfied (Vallier 2016;Wall 2022), ensuring, respectively, that one's reasons can be evaluated by others and that they can be endorsed. 2By complying with the public justification requirement (conditioned by acceptability and publicity), coercive political rules, such as laws, can be justified, as they then would not violate norms of equality, freedom and/or respect.
However, precisely because the public justification requirement bases its standard of legitimacy on whether public justifications fulfil conditions of publicity and acceptability, rather than accuracy or veracity, it seems epistemically unreliable: The public justification requirement permits that public justifications of political rules can partly consist of false beliefs and that correct beliefs are excluded from public justifications if they are based on reasons not evaluable and/or acceptable to some.Ultimately, this epistemic unreliability risks undermining the legitimacy criterion of PRL: While it may seem intuitively appalling to coerce people to comply with political rules the reasons for which they cannot accept or even evaluate, it also seems illegitimate to coerce them to comply with rules the reasons for which are based on literally false beliefs.
In this article, we present an epistemic approach to justifications of political rules, to move beyond the epistemically unreliable public justification requirement in PRL. 3  Drawing on epistemological theories of argumentation, we demonstrate that it is possible to assess justifications based on their epistemic meritsthat is, whether they promote rationally justified belief.By focussing on the justificatory dimension, our epistemic approach makes it possible to assess justifications in terms of their epistemic quality even when it is difficult or impossible to establish the truth.This approach allows people or policymakers to justify coercive political rules in terms of their comprehensive doctrines yet also submit their justifications to rigorous epistemic scrutiny.
The article chiefly makes three contributions: First, it expands the field of legitimacy theory by demonstrating a feasible alternative to the public justification requirement in public reason liberalism.Thus, we address 'the classic question of liberal political thought': How to ensure the permissibility of coercive political power (Stears 2007, 536).Second, more specifically, questioning the blanket exclusion of comprehensive doctrines from public justifications, we provide an epistemologically informed approach for comparatively assessing any justifications of coercive political rules, whether grounded in comprehensive doctrines or not, in terms of their argumentative robustness.Third, advancing beyond standard objections to PRL, we demonstrate that our epistemic approach is well-equipped to promote the value public justification serves, viz.respect for personal autonomy.
The article is structured as follows: In Section 2, we introduce PRL and argue that the public justification requirement is epistemically unreliable, since it fails to prioritize both the inclusion of true beliefs and the exclusion of false beliefs in justifications of political rules.In Section 3, we evaluate two attempts to address the epistemic challenge from within PRL, which proceduralize acceptability and idealize the subjects, respectively.
Finding both insufficient, we conclude that we need to move beyond the public justification requirement to formulate epistemically sound criteria for assessing justifications of political rules.In Section 4, we argue that focussing on justification provides a way to handle this challenge, and, by drawing on argumentation theory, we also demonstrate what an epistemic approach to justification might look like.In Section 5, we defend our epistemic approach against three weighty objections, before we conclude.

Why the public justification requirement is epistemically unreliable
Public reason liberalism (PRL) holds that justifying authoritative political rules, especially if they involve coercion, requires more than providing adequate grounds: the reasons offered should also be public in the sense that they correspond to the values and beliefs of the persons who are subject to the rule.While the question about how to justify the coercive nature of public power has a long pedigree in political thought, the predominant theme in contemporary political philosophyan agenda set by key thinkers such as John Rawls (1996), Gerald Gaus (1996), Jürgen Habermas (1992) and othersis not justification simpliciter, but justification to 'a particular set of persons' (Simmons 1999, 759;cf. Chambers 2010;Quong 2022).On the PRL view, a political rule (e.g. a law) is unjustified and illegitimate unless it meets the public justification requirement, regardless of whether the rule was based on correct grounds.Consequently, when policymakers or citizens seek to justify coercive political rules, they should present reasons that the members of the relevant public could accept, rather than appeal to what they themselves hold to be truths in moral and political matters. 4  The rationale for subjecting the justification of political rules to this intersubjective constraint is to maintain societal stability, respect and freedom for citizens, while still enabling the state to exercise coercive public power in pluralist societies: 'The move away from justification simpliciter toward inter-subjective ideas of justification is due in part to the accommodation of and respect for the deep pluralism that characterizes most liberal societies… there is a general acknowledgment that getting the argument right does not confer any moral authority to impose that conclusion on people who do not agree with the argument.'(Chambers 2010, 894) Consequently, public justification is internal, intersubjective and interpersonal, and can be distinguished from impersonal or correctness justifications, which rely on external criteria such as facts and soundness, to assess the legitimacy of political rules (Van Schoelandt 2015;Wall 2010).
In rejecting external criteria of correctness, PRL shares the agnosticism or scepticism to truth which has been influential in contemporary political philosophy.Not only moral reasons motivates PRL to reject controversial or non-evaluable truth claims as a foundation for its notion of legitimacy, but also the so-called 'burdens of judgment' (Rawls 1996, 55ff): Human reason has its natural limits, whichapart from prejudice, irrationality or self-interestprevent rational people from arriving at common conclusions about truth in the complex terrain of politics.In cases of thick reasonable disagreement (Valentini 2013)that is, when people reasonably disagree not only about substantive claims but also about the truth conditions of those claimsthey simply cannot resolve their disagreements by invoking external, procedure-independent standards of truth or correctness 'on which even heated philosophical debates proved endless' (Caluwaerts and Ugarriza 2012).And even if people could agree on what the relevant standard is, they might still disagree over how a particular political rule measures up against it (Ingham 2013).We shall refer to this scepticism about truth claims in politics as the 'objection from disagreement' (cf.Gerlsbeck 2018).
Of course, not all contemporary political theorists share this scepticism toward truth claims in politics. 5For theorists who allow truth a greater role to play, PRL may seem epistemically suspect, since the public justification requirement implies that a coercive political rule may be justified in terms of reasons that contain false beliefs, if the subjects can accept the reasons.Conversely, the public justification requirement entails that we can dismiss as illegitimate a coercive political rule that is justified in terms of reasons that contain correct beliefs, if those reasons aren't ones the subjects could accept.As such, the public justification requirement implies epistemic trade-offs since it requires that the justification of political rules should correspond to the values and beliefs of the persons who are subject to the rule, rather than to standards of correctness.Thus, the public justification requirement is epistemically unreliable as it is both too inclusive and too exclusive: It prioritizes neither the exclusion of false beliefs nor the inclusion of true beliefs.

Mitigating the epistemic unreliability of the public justification requirement
How have PRL proponents addressed the epistemic unreliability of the public justification requirement?In this section, we shall analyze two approaches that suggest PRL could address the epistemic challenge yet hold on to the public justification requirement: Proceduralization approaches, first, suggest that if the implementation procedure is acceptable to all, citizens can be allowed to justify substantive political rules in terms of their comprehensive doctrines.Idealization approaches, second, instead assume idealized subjects with more epistemic competence than epistemically fallible actual human beings.We shall argue that both approaches ultimately fail to address the epistemic unreliability problem in a satisfactory manner, which strengthens our case for seeking alternatives to the public justification requirement.

Proceduralizing acceptability
Some epistemically oriented theorists have proposed ways to reconcile an epistemic approach with PRL in general and the public justification requirement in particular.For instance, David Estlund (2012, 253) endorses the acceptability conditioneven though he acknowledges that it implies not prioritizing the exclusion of false views, but rather giving 'moral standing to certain viewpoints even if they are mistaken'.To square truth claims based on comprehensive views with public reason, Estlund proposes a revised 'epistemic political liberalism', which is based on distinguishing between different levels of justification: 'At one level, the reasons [for or against a law] are about the procedure.At another level, the reasons are the ones that are to be given within the procedure' (Estlund 2012, 269).Unlike the standard PRL view, epistemic political liberalism would allow citizens to justify their endorsement of a certain law based on comprehensive doctrines 'within the procedure', while procedural reasons should be given when the law is implemented.If the procedure is acceptable to all reasonable points of view, implementation of the law conforms to the public justification requirement even though citizens earlier endorsed the law on the basis of comprehensive doctrines.Consequently, in this revised version, the public justification requirement is compatible with truth claims dependent on comprehensive doctrines, if the implementation of public rules is justified by procedural reasons, for instance, that a majority voted in favour of the law in question.
While this revised epistemic political liberalism is preferable on epistemic grounds to standard PRL, it generates problems of its own.First, this approach does not seem compatible with the commitments of PRL.Estlund (2012, 271) suggests that what serves as justification is not the different doctrines people adhere to (and disagree about), but rather the 'epistemic value of public deliberation in which participants press their comprehensive views about true justice'.Yet if we are correct to interpret this deliberative fallback as purely procedural, then the substance of deliberation about a political rule can consist of any kind of considerations. 6Furthermore, deliberation need not consider the rule's impact on values such as equality, liberty, dignity or civil peace.Such a thin conception of the public justification requirement would hardly be able to serve its basic function: to legitimize public coercion by offering reasons that are acceptable to those who would be subject to the coercion (for a similar critique, see Talisse 2012).Additionally, a purely procedural account of the public justification requirement seems hard to maintain: Since there is reasonable dispute over the epistemic value of public deliberation, it cannot be justified in purely procedural terms; it also needs to be supported on substantive reasons.Hence, it is doubtful, at the least, whether Estlund's epistemic political liberalism is compatible with basic commitments of PRL.
More importantly, though, the revised epistemic political liberalism view is epistemically unreliable.Estlund focusses on making his epistemic approach compatible with public reason liberalism, while the question about how to improve justifications of political rules epistemically has much broader relevance.For instance, even if a purely procedural version of the public justification requirement might address the risk of excluding true beliefs, it fails to address the inverted risk, viz.including false beliefs, which a truly epistemic approach to justification should also consider.While deliberation as such might be truth-tracking, the revised epistemic political liberalism view offers no epistemic criterion for detecting false beliefs in the output of the process.Hence, from an epistemic point of view, the revision is insufficient, regardless of whether it is compatible with the public justification requirement or not. 7

Idealizing the subjects
Another way to reduce the risks of both excluding correct beliefs and including false ones is to idealize the people in relation to which political rules should be justified.The rationale behind this move is to address the fact that humans are fallible, which means that they sometimes 'fail to actually endorse what they have reason to either because of errors in reasoning, biases or poor information' (Van Schoelandt 2015, 1035).By idealizing the subject, we consequently need not take our point of departure from what the subjects actually endorse, but rather from what they should have endorsed according to normative standards of rationality.
Proponents of PRL differ on how much idealization they think is needed.On strong idealization accounts, the subjects are 'exemplary epistemic agent' which are 'highly idealized versions of actual political subjects' (Wall 2016, 220), while on weaker idealization accounts we should consider only what political subjects would have recognized after a 'respectable amount' of reasoning (Gaus 2015(Gaus , 1087)).Idealization is not primarily motivated by epistemic concerns but rather by concerns about how to reconcile freedom and equality with public authority (Rossi 2014;Van Schoelandt 2015): As we cannot expect to be able to justify coercion to people based on what positions they actually hold, we need to narrow the scope of possible views in relation to which we should justify political rules, which is achieved through idealization (Enoch 2015, 117f;Quong 2022;Van Schoelandt 2015;Vallier 2018).However, idealization can also promote epistemic values: By starting from what people ought to endorse, according to normative standards of rationality, rather than from what they actually endorse, we can favour rational justifications of political rules, and thereby promote the exclusion of false and the inclusion of correct beliefs (Wall 2016).
However, idealization is a double-edged sword for proponents of PRL.While stronger idealization admittedly promotes the epistemic value of justification, it comes at a cost for those wholike proponents of PRLendorse interpersonal justification.Idealization creates a distance between what the subjects actually endorse and what they should endorse according to various degrees of idealization.Now, if the actual views of persons subject to coercion are quite different from the views they should endorse, then the relevance of the public justification requirement is undermined since what the subjects should accept is quite different from what they actually accept.It is simply 'strange to claim a law is justified to an agent when the justification appeals not only to evidence and values she lacks, but to reasoning she, with her human cognitive limitations, could never complete' (Van Schoelandt 2015;cf. Rossi 2014;Bohman and Richardson 2009) .
Consequently, if proponents of PRL use idealization as a tool for promoting the epistemic status of justifications, they run the risk of undermining the very rationale of interpersonal justification: The claim that justifications of political rules should be public in the sense that the reasons correspond to the values and beliefs of the persons who are subject to the rule.Some critics of PRL claim that idealization as such undermines the normative relevance of interpersonal justifications (Enoch 2015).If so, then PRL proponents cannot use idealization to promote the exclusion of false and inclusion of correct beliefs, and even if they would deny this radical conclusion, they anyway face the less Friberg-Fernros and Karlsson Schaffer controversial claim that strong idealization threatens the normative relevance of interpersonal justification.And since the epistemic gains are greater the stronger the idealization, proponents of PRL apparently cannot resort to idealization to meet the epistemic challenge of promoting the exclusion of false and the inclusion of correct beliefs.
To conclude, seeing that both proceduralizing and idealizing approaches struggle to address the epistemic unreliability problem, we take this as a reason to move beyond the public justification requirement to explore alternative standards of legitimacy.

An epistemic approach to justifications of political rules
In this section, we turn to presenting our epistemic account of justification as an alternative to the public justification requirement in PRL.As we showed earlier, the scepticism towards truth claims in PRL is not only based on moral reasonsthat is, the view that coercive political rules must be justified interpersonallybut also on assumptions about natural limits of human rationality, which warrant the so-called objection from disagreement.This objection is not only relevant for PRL but also, obviously, for an epistemic account of justification of coercive political rules, as such an account aims to ground justification on facts about the state of affairs.However, rather than seeking to nullify this objection head on, we shall suggest that our epistemic approach can bypass it.By shifting focus from whether public justifications are based on correct premises to whether justifications comprise strong arguments, we can assess an important aspect of epistemic quality even when the truth may be difficult to know or to agree upon. 8 While the concept and practice of justification is vitiated by controversy, we need only define justification in its most basic terms for the purpose of this article: To justify something is to provide ground for believing something (Alston 1985).On this basic definition, one can evaluate the epistemic status of justifications without necessarily being able to conclusively respond to the sceptics' objections.For instance, regardless of whether we can know the truth about some particular question, wishful thinking (i.e.believing something to be true because you want it to be true) is a poor epistemic ground for believing something.Furthermore, it is plain to see that some kinds of justifications, for example, modus ponens, are truth-preserving, while others, for example, 'affirming the consequent' are not.Hence, there are criteria we can apply to assess and improve the grounds for believing something, even if we do not know for sure whether the belief is true or false.
The fact that we can assess the grounds for a belief independently of its truth also illustrates why justification is desirable.For one thing, when we seek to justify our beliefs, we also increase the likelihood that we will identify true beliefs, by scrutinizing the plausibility of premises and following the laws of logic, even if complying with these rules does not guarantee that we will end up with the correct conclusion (Friberg-Fernros and Schaffer 2017; Roush 2007).As already Plato notes, by providing supporting reasons, justifications give us more well-grounded beliefs than if we arrive at the truth merely by chance or unintentionally (Ichikawa and Steup 2017).Moreover, in a political context, a justified true belief would seem more legitimate, compared to a mere true belief, as a ground for decision making, since people by nature want to know why certain actions are taken while others are not (Friberg-Fernros and Brommesson 2013;Hartmann and Sprenger 2012).In contemporary political theory, this need for reason-giving as a basic criterion of legitimate authority comes in many different guises (Forst 2007;D. F. Thompson 2008;Waldron 1987).Hence, the value of justification is widely recognized. 9

An epistemic criterion for assessing justifications of political rules
Thus far, we have identified a need for an epistemic account of justification of coercive political rules, that is applicable also in cases in which the truth is unknown.Since justificationthe act of providing grounds for believing somethinginvolves argumentation, that is, making claims based on premises by a method of reasoning, we shall now draw on the epistemological theory of argumentation to propose a way of assessing the quality of justifications of political rules.
Since any reasonable epistemic criterion for justifications of political rules should be practicable, we can rule out criteria that are too strict.The epistemically strongest type of justification would be a sound inference, that is, an argument in which the conclusion necessarily follows from the true premises.However, admitting only sound inferences would make the criterion impracticable.First, while deductive reasoning requires the conclusion to follow necessarily from the premises, the by now established field of informal logic suggests that it is also legitimate to draw conclusions that do not necessarily but probably follow from the premises (Johnson 1999).Second, while a sound inference requires that we can establish with certainty the truth of the premises (Groarke 2019), a workable epistemic criterion should allow for assessing justifications when we cannot establish the trutharguably a more common circumstanceyet can at least come closer to it by detecting argumentative weaknesses.One can use such a workable, minimalistic criterion, we shall argue, to evaluate justifications of political rules even if one accepts the objection from disagreement.
The epistemological theory of argumentation (Aikin 2008;Biro and Siegel 2008;Lumer 2005Lumer , 2011) can be distinguished from the main rival accounts of argumentation in terms of how they model the function of argumentation.Rhetorical theories assume that argumentation aims at persuading an addressee, while consensus theories assume that argumentation serves to reach shared beliefs through a discursive process. 10By contrast, the epistemological theory of argumentation assumes that the purpose of argumentation is to produce rationally justified belief.An advantage of the epistemological approach is that it offers criteria for assessing an argument's epistemic value, that is, whether the inference is adequately supported by the premises and to what extent the premises are plausiblewhich is why it seems promising for devising tools for identifying argumentative weaknesses that may hamper the truth.
The epistemological approach suggests that different types of argumentsso-called argument schemesare governed by different epistemological principles (Lumer 2011;Walton, Reed, and Macagno 2008).There are numerous argument schemes, but they are usually categorized into at least two broader classes: Deductive and inductive argument schemes.While deductive argument schemes can be evaluated based on standard rules of formal logic, inductive argument schemes offer a special challenge that the epistemological approach addresses in a compelling way, which we'll focus on in the following.All inductive argument schemes rest on probabilistic epistemological principles, which means that the conclusion can be wrong even though the premises are true, but they can promote the truth to different degreesboth due to how the arguer uses the scheme and due to its inherent epistemic potential.Therefore, we can distinguish between two distinct, generic ways in which truth can be hampered by the use of (inductive) argument schemes: Either the argument scheme as such fails to convince because it rests on an inadequate epistemological principle, or it fails because the arguer applies the scheme in a distorted wayeither by using it incorrectly or by resting it on implausible premises (Friberg-Fernros and Schaffer 2017).
By applying the epistemological approach systematically, one can evaluate and rank different kinds of argument schemes with regard to their epistemic value.Being able to distinguish better and worse argument schemes is crucial, since it opens for promoting the truth in political decision making by detecting argumentative weaknesseswhich is possible even granting that the objection from disagreement is sound.To illustrate the first type of errorargument schemes that rest on an inadequate epistemological principleconsider 'wishful thinking' and its negative counterpart, 'argumentum ad consequentiam': These argument schemes suggest an event will (or won't) take place because it has positive (negative) consequences (Lumer 2000, 414) and they obviously rest on an inadequate epistemological principle, since the probability of something taking place does not (generally) depend on whether or not someone wants it to happen.No matter whether these schemes rest on true premises and are applied in ways that realize their (almost nonexisting) epistemological potential, the scheme itself is an obstacle to correct conclusions.Such schemes are inferior to most other schemes.Likewise, some schemes seem to be more commensurable and therefore easier to rank above others.For instance, 'argument from consequences' seems to have a stronger epistemological warrant than 'argument from threat', since the former, unlike the latter, considers not only potential negative but also potential positive effects (Friberg-Fernros and Schaffer 2017).
Secondly, one can also detect obstacles to truth when an arguer uses inductive argument schemes in distorted ways.According to argumentation theory, the use of specific argument schemes should be guided by a specific set of critical questions.For instance, when using 'argument from consequence', the arguer should ask herself what are the probabilities for the intended consequence, for alternative effects and for (negative) side effects to occur, as well as whether there are aspects other than consequences that should be considered (Walton et al. 2008, 332f).Each argument scheme has its own set of critical questions one must run through to evaluate whether it has been adequately used.The epistemological approach to argumentation posits that if the arguer satisfactorily answers these critical questions when applying an argument scheme, she is more likely to arrive at a correct conclusion.Granting that this is the case, the extent to which these questions are unanswered can be seen as an indicator of a distorted use of the argument scheme which, in turn, would decrease the probability of arriving at correct conclusions.Thus, for inductive argument schemes, too, there are ways of detecting obstacles to truth in the justification of public ruleseven if we grant that the objection from disagreement is true.
The epistemological theory of argumentation contributes to the distinctiveness of an epistemic approach to the justification of political rules in two ways.First, since the epistemological theory of argumentation allows us to rank different argument schemes in relation to their epistemic value, we can use it to evaluate and compare justifications of public rules.For instance, we showed above that 'wishful thinking' is inferior to most other justifications, and that 'argument from consequence' is stronger than 'argument from threat'.
One can use this epistemological ranking of arguments to assess justifications of political rules.For example, a justification based on 'argument from authority' is likely to be weaker than an argument that is not evidentially dependent on the epistemic accuracy of a certain authority but where the inference rather concerns the substantive position.To illustrate, compare an argument (a) against the death penalty which only refers to international human rights law instruments banning the practice (an appeal to authority) with an argument (b) that focusses on, for example, the death penalty's irreversibility, lack of deterrent effect and/or inherent inhumaneness (variants of the scheme value-based practical reasoning (Walton et al. 2008, 324)).Even if we can verify that the premises of (a) are true (optional protocols to core international human rights treaties do in fact ban the death penalty, etc.) and that the conclusion follows, the relevant authority may still be mistaken.However, if in (b) we correctly use the various practical reasoning argument schemes against the death penalty (e.g. that practicing the death penalty involves a risk of punishing innocent persons, which is indefensible given its irreversibility, and so on), we have presented a case against the death penalty that is epistemically stronger, ceteris paribus.Hence, by leading us to assess the heart of the matter, many argument schemes avoid the inherent epistemic weakness of argument from authority. 11 Furthermore, consider the debate over religious truth claims in public justification (for an overview, see Eberle and Cuneo 2017).Some religious truth claims are justified by arguments from divine authority, that is, allegedly mediated by God, while other religious truth claims are claimed to be justified by natural reason (Audi 2009).For instance, the Judeo-Christian concept of Imago Dei, which some invoke to justify the concept of human dignity, can be seen as a revelatory claim from God about the status of human beingsan argument from (divine) authority.However, others working from the same comprehensive doctrine seek to establish that due to our rational nature, human beings must have a divine origin, which in turn provides a non-revelatory support for Imago Deian 'argument from alternatives' (i.e. that nothing other than divine origin can explain the human rational nature).Whether plausible or not, this argument differs in kind from arguments that presuppose a divine authority, which, at least ceteris paribus, are epistemically weaker due to concerns about the accuracy of interpretation, the reliability of commandment and the authority of the source.
Likewise, justifications based in comprehensive moral (non-religious) doctrines can be expressed in terms of epistemically stronger or weaker argument schemes.Consider, for instance, 'argument from waste'an argument scheme commonly used in both public debate and everyday decision making that invokes a utilitarian logicwhich consists in saying one should continue a course of action because otherwise one's prior investments in the action would be lost (say, to continue a public infrastructure project despite severe unforeseen problems, because otherwise the taxpayers' money already spent would be wasted).It is usually considered faulty reasoning: A sunk costs fallacy (for some exceptions, see Walton 2002).A utilitarian justification of a political rule would be epistemically stronger if it rather took the form of an 'argument from consequences' that includes opportunity costs and discounts sunk costs in the calculus.Whether we accept or not the utilitarian premise, the 'argument from consequences' is epistemically preferable to an 'argument from waste', ceteris paribus.
Second, applying the epistemological theory of argumentation to justifications of political rules makes it possible to scrutinize justifications for obstacles to correct conclusions.As we noted above, each argument scheme can be evaluated on the basis of a specific set of critical questions (Walton et al. 2008).To illustrate how this evaluation might be done, let us consider policy debates on climate change.Here, arguers often invoke (or dispute) climate researchers, which is an example of an 'argument from expertise', and the critical questions one needs to ask for this scheme includes establishing the relevance of the field of expertise, the reliability of the expert and the consistency with other experts' opinions.Furthermore, if someone claims that measures must be taken (or not) to curb greenhouse gas emissions in order not to exceed the global warming targets, they are using an 'argument from consequence', for which one must ask questions about the likelihood and the (dis)value of the consequences of the measures as well as about the likelihood and (dis)value of any side effects of such measures.Likewise, 'arguments from cause to effect' on this issue raise questions about the strength of the evidence of the causal connection and whether there is evidence of other causes.
When one evaluates justifications of proposed measures (which usually entail establishing political rules) on any policy issue, addressing the critical questions related to each specific argument scheme increases one's chances of detecting obstacles to correct conclusions, even in cases where we are uncertain about the truth on the matter.For instance, to argue in favour of a certain course of action based on its consequences without considering the (expected) value of the consequences of alternative actions would likely lead to a false conclusion, even if we do not know the truth on the matter.Consequently, the higher the epistemic quality of the argument schemes we use and the more accurately we apply them, the better our chances to avoid obstacles to correct conclusions, even if we grant that the objection from disagreement is true.

The moral demands of the epistemic approach
To further define our epistemic approach to justification, let us first clarify the moral demands that follow from it and then explain how it provides clearer criteria of legitimacy than the public justification requirement in PRL.In the next section, we'll address some weighty objections against the epistemic approach to further demonstrate its advantages.
A key question concerns the addressees of the epistemic approach to justification: Who should use it when assessing or formulating justifications of political rules?What are reasonable requirements on citizens, policymakers or public officials in terms of evaluating the epistemic quality of arguments for or against political rules?Would ordinary people be able to evaluate the epistemic quality of arguments?Answering these questions, we first submit that the approach can apply in any context where agents justify political rules: It is imperative on the state justifying its policies to affected citizens or the public, but it may also guide the private judgment of both citizens and public policymakers. 12 Moreover, we can establish that empirical research on persuasive reasoning has found that laypersons and even children are able to differentiate between better and worse applications of argument schemes (Hoeken et al. 2012;Hoeken and Schellens 2014;Hornikx and Hahn 2012).Hence, the normative standard that derives from the epistemological theory of argumentation seems to correspond to an inherent cognitive capacity in human beings (which, of course, is fallible and unevenly distributed).While the cognitive ability in itself obviously does not make people immune to biased reasoning (Kahan et al. 2017), recent research suggests that the saliency of civic norms actually makes people more inclined to evaluate arguments in an epistemically adequate way (Mullinix 2018).Consequently, people in general seem to be able and motivatable to evaluate the epistemic quality of public justificationsat least to some degree.
However, it seems reasonable to place different demands on ordinary citizens on the one hand, and policymakers or public officials on the other, because the latter unlike the former exercise public power (cf.Bardon 2018, 654).Since the decisions policymakers and public officials make in the capacity of their office typically are authoritative, in the sense that subjects have a duty to obey and the state has a right to coerce non-compliers, they have at least a prima facie moral duty to provide and present the best possible justifications of the political rules they impose.While the epistemic demands on citizens are lower, morality still motivates at least minimal epistemic duties on citizens, for example, that they request and assess reasons for and against election campaign promises.
Turning to advantages, we submit that the epistemic approach offers a stronger criterion of exclusion and a simpler conception of legitimacy than PRL.First, PRL holds that the state should justify political rules based on reasons all citizens could accept (Bohman and Richardson 2009).Consequently, reasons dependent on comprehensive doctrines are ruled out as unreasonable.The epistemic approach, by contrast, suggests that the state should justify political rules in terms of arguments of high epistemic quality, and disqualifies reasons based on their insufficient epistemic quality.Ironically, although the epistemic approach dispels the public justification requirement, its criterion of exclusion may seem more acceptable to citizens whose views are excluded, since it only tells them they need to present more convincing arguments, rather than dismissing their ethical worldviews as unreasonable.
Second, where PRL suggests that legitimacy entails justifying political rules in terms of reasons all can accept, the epistemic approach suggests that legitimacy entails justifying political rules in terms of strong arguments.Compared to PRL, the epistemic approach's conception of legitimacy is simpler and more direct: An authority can seek to issue justifications of political rules that meet the epistemic criteriaby properly scrutinizing the reasons that are invokedwithout knowing in detail whether and how those justifications resonate with the values and beliefs held by its subjects.Therefore, the conception of legitimacy is not only less arbitrary but also more accessible since normative legitimacy can be assessed independently of whether it corresponds to the substantive values and beliefs held by the subjects.

Objections to the epistemic approach to justification of public rules
As we have thus far sought to demonstrate the potential of an epistemic approach to justification of political rules grounded in the epistemological theory of argumentation, let us now address three potential objections: (a) That the public justification requirement is a moral imperative, and that it is therefore wrong to force someone to obey a political rule the justifications of which they do not accept or understand; (b) that the epistemic approach is insufficient, as it cannot determine whether inferences in justifications of political rules are sound or not; and (c) that abandoning the public justification requirement is a slippery slope, inviting people to pursue doctrines that might undermine the stability of liberal democracy.Responding to these objections helps us further to explain the epistemic approach and how it advances on PRL.

The public justification requirement is a moral imperative
The first and most fundamental objection relates to the moral permissibility of our epistemic approach.Pursuing this objection, one might agree that there are epistemic reasons to question the public justification requirement, but nevertheless maintain that we need to adhere to it for moral reasons, as it prohibits forcing people to comply with political rules whose moral justifications they cannot accept or even evaluate.One version of this objection might hold that it is disrespectful to coerce someone to obey a rule based on reasons they find unacceptable or merely unevaluable, as it denies their rational capacity to grasp and act on argument; another version might claim that it would be unjust to blame someone for violating a rule whose justification was unacceptable or unevaluable to them.
Responding to both versions of this objection, we shall argue that there are alternative ways to advance the values of respect for persons' autonomy and of not unjustly blaming persons for violating rulesand among these alternatives, our epistemic approach has a comparative advantage.First, PRL is not the only way to ensure that authoritative institutions respect the autonomy of persons and do not blame them unjustly for violating rules.The public justification requirement aims to ensure that political rules are publicly justifiable, that is, acceptable to everyone.If authorities meet this aim, they respect people's ability to grasp and act on arguments and can justly blame them if they violate the rules, and PRL grants this aim primacy, since political rules that are not publicly justified are necessarily illegitimate.However, we can pursue this aim without prioritizing it as strongly as in PRL.Even if one rejects the public justification requirement, one can recognize the moral value of political rules being publicly justifiable as a good-making quality of political rules; for instance, one can readily acknowledge that, ceteris paribus, it is morally preferable that political rules are publicly justified than that they aren't (Wendt 2019, 46).Consequently, our position does not imply that interpersonal considerations are morally irrelevant, but only that they should not constitute a requirement.
Second, among the accounts that reject the public justification requirement, our epistemic approach to justification seems particularly well-suited to pursue the value of publicly justifiable rules, because unlike the alternatives, it is not grounded in a specific substantive philosophy, such as perfectionist liberalism.Rather, the epistemic approach aims to make room for well-grounded truth claims whatever they might be.Arguably, this inherently non-sectarian starting point of the epistemic approach is an alternative source of publicness that contributes to the legitimacy of justifications.Moreover, by drawing on the epistemological theory of argumentation, our epistemic approach provides concrete analytical tools by which reasons can be critically examined.In turn, such scrutiny also promotes the publicity of justifications.Put differently, by offering subjects the best argument for a certain political rule, an authority can promote the value of respecting their ability to act on argument and also foster the general acceptance of political rules, thereby reducing the risk that people are being unjustly coerced by political rules and unjustly blamed for violating them.
However, proponents of PRL might still insist that even if alternative approaches contribute to the publicity and acceptability of justifications of political rules, the public justification requirement provides a necessary minimum since it is never legitimate to enforce such rules on persons who find the justifications unacceptable or merely unevaluable.Accordingly, the public justification requirement would be categoricalthat is, political rules are 'legitimate only if they are publicly justifiable' (Wendt 2019, 41).
While it is beyond the scope of this article to rebut conclusively the claim that the public justification requirement is categorical, suffice it to say that the claim is by no means universally accepted.Proponents may think PRL is 'the only game in town', but its critics believe it 'has been refuted several times' (Enoch 2015, 112).For instance, critics have pointed out that treating the public justification requirement as categorical has consequences that contradict widely shared moral intuitions (Eberle 2002;2009;Enoch 2013;Lott 2006); that PRL is self-defeating because the idea itself will be unable to meet the public justification requirement (Enoch 2013;Raz 1998;Wall 2002); and that PRL requires privatization of comprehensive doctrines (e.g.religious faiths), which entails an asymmetrical justificatory burden (Eberle 2002;March 2013;Wolterstorff 1997). 13Of course, whether such objections succeed or not may depend on which specific version of PRL they address (Billingham and Taylor 2020), but they do show that the relevant jury is still out on whether the public justification requirement should be treated as categorical.
Furthermore, the epistemic approach we have proposed may suggest a different challenge than standard objections to PRL, because it does not rest on any substantive doctrinal content.The key argument for the public justification requirement holds that the state would disrespect citizens by coercing them to comply with political rules the reasons for which they cannot accept.This may seem plausible if one assumes the state would justify its coercion in terms of a comprehensive doctrine (say, utilitarianism, Kantianism or Catholicism).However, the epistemic approach does not accommodate any doctrinal content; rather, it is grounded in argumentative rationality.Thus, the disrespectfulness argument is less effective against the epistemic approach than against objections to PRL that are grounded in a specific comprehensive doctrine.
We therefore conclude that the epistemic approach can promote the moral values informing the public justification requirement.Moreover, the fact that the public justification requirement is by no means universally accepted as being categorical means that it is more reasonable than not to give the epistemic approach the benefit of a doubt.

The epistemic approach to justification is insufficient too
Another potential objection holds that we gain little by the epistemic approach compared to approaches that adhere to the public justification requirement, since the epistemic approach won't allow us to establish in general whether inferences in justifications of political rules are sound or not.On the contrary, the epistemic approach quite modestly focusses on demonstrating how to detect obstacles to correct conclusions and it seems that both approaches, in the end, tend to avoid the truth.Put differently, like PRL, the epistemic approach can accept 'the fact of reasonable pluralism' and that it is simply unrealistic to think that people would be able to convince one another about the correctness of substantive positions (i.e.'comprehensive doctrines').For PRL, this pluralism motivates the public justification requirement, which based on moral considerations limits the range of permissible reasons in justifications of political rules. 14For the epistemic approach, however, pluralism rather motivates an epistemic humility: Since we cannot always with certainty establish the truth of the premises (due to reasonable pluralism), we will often be unable to justify political rules based on sound inferences.
However, even under conditions of reasonable pluralism, people may be able to rationally convince one another that some justifications are epistemically stronger than others, and even that some ought to be rejected because they rest on epistemologically weak argument schemes and/or use them in distorted ways. 15Hence, our approach provides tools for examining truth claims epistemically even if we cannot establish their truth value with certainty.Since the legitimacy of political rules does not depend on whether an overlapping consensus or convergence between citizen's comprehensive doctrines can be established, a political rule might be legitimate even if it is justified by a disputed comprehensive doctrine alone as long as the justification has withstood scrutinythat is, is epistemically valid.Consequently, while the epistemic approach is insufficient to allow us to establish the truth of the matter in all cases, it advances on approaches that submit to the public justification requirement by allowing a wider scope of reasons in justifications of coercive political rules.

Abandoning the public justification requirement threatens stability
A third potential objection to our epistemic approach holds that if abandoning the public justification requirement entails an 'anything goes' approach to justification of coercive political rules, it might threaten democratic stability.Proponents of the public justification requirement might object that it is not only justified by respect for persons; it also helps promote the stability that pluralistic societies need (Eberle and Cuneo 2017;Kaufman 2009;Rawls 1996).For instance, without the public justification requirement, adherents of different religions could pursue their doctrines as reasons for political rules, which might not only be disrespectful but also threaten the stability of a liberal democratic society.
We will offer a two-pronged response to this objection: First, we admit our epistemic approach is more permissible than most approaches informed by the public justification requirement, since it permits that, for example, religious reasons could be used to justify public rules.However, this is an advantage, not a weakness. 16It seems both unfair and epistemically unwarranted to rule out, by definition, religious doctrines as a potential justification for political rules regardless of their epistemic status.We noted above that revelatory claims as a justification for political rules are inherently problematic and ceteris paribus inferior to other types of claims, and that not all religious claims are revelatory.Non-revelatory religious claims should be evaluated according to the same epistemic standards we use to evaluate any other types of claims.Thus, our approach's permissiveness to religious claims in this regard is justified.
While the first prong of our response to the objection admits that our epistemic approach is more permissive than the public justification requirement, the second prong suggests that the approach is at the same time quite strict, as it provides tools by which, for example, religious claims can be scrutinized rigorously.As we noted above, religious doctrines are sometimes claimed to be mediated by God, which in turn means that they rest on an 'argument from authority', which normally is an epistemologically weak argument scheme.The 'argument from divine authority', however, is even weaker than an appeal to a worldly authority, since there is no certainty that God actually exists, and problems that vitiate arguments from authority in general, such as whether the message is correctly interpreted, are even more problematic in this case.Because of such problems, revelatory religious claims are unlikely to meet the epistemic standards of a good argument; therefore, in turn, the epistemic approach we have suggested here is unlikely to admit them as justifications of political rulesbut it does not rule out that possibility a priori.Compared to approaches based on the public justification requirement, which for moral reasons reject religious reasons and other comprehensive doctrines, we submit that this matter-of-factly way of dealing with religious reasons is more defensible.
The non-sectarian way to approach comprehensive doctrines may furthermore also contribute to stability in pluralistic liberal societies.Empirical research suggests that discrimination of religious minorities tends to occur when 'state resources are used to support a select religion or the state holds a strong secular ideology' (Finke, Martin, and Fox 2017, 411).Approaching secular or religious comprehensive doctrines epistemically provides a way to avoid such ideological or religious favouritism and the enforcement of coercive political rules that it often justifies.That is not only good in itself but also promotes stability.

Conclusion
The core argument of this article is that public reason liberalism's public justification requirement is unreliable from an epistemic point of view, since it permits both the inclusion of false beliefs and the exclusion of correct beliefs in the justification of coercive political rules.To move beyond the public justification requirement, the article has taken on the challenge of formulating an epistemic standard of legitimacy for political rules that is applicable even when the truth may be difficult to establish or agree on.By drawing on the epistemological theory of argumentation, according to which argumentation aims to reach rationally justified belief, we have provided an epistemic approach to justification that enables assessing the epistemic quality of public justifications.
Offering an alternative to the public justification requirement, our epistemic approach to justification is a key contribution of the article.Addressing some potential objections to our approach allowed us to further detail what it entails and how it advances on the public justification requirement.Crucially, compared to the public justification requirement, the epistemic approach is more permissive to comprehensive doctrines, thus allowing citizens and policymakers to justify political rules in terms of, for example, religious, metaphysical or ideological beliefs that might not be acceptable to all, yet at the same time it is strict, since it provides standards by which to assess the epistemic quality of such justifications.
Elaborating an epistemic approach to the justification of public rules would be a truly ecumenical concern, because regardless of whether one submits to the public justification requirement, both proponents and critics of public reason liberalism can nevertheless reach agreement on the aim to weed out epistemically weak justifications.Identifying and eliminating justifications that fail to meet the relevant epistemological criteria does not in itself imply any position about whether comprehensive doctrines alone can justify public rules.Therefore, even if this normative question is important and determines the extent to which epistemic concerns should matter, all participants in this debate could probably agree that epistemic concerns should matter to at least some degree.This ecumenical task should indeed be a shared concern at a time when fact resistance and conspiracy theories seem to be on the rise.

Notes
We wish to thank the anonymous reviewers for their constructive comments; Delitalia for providing the venue where we developed this argument over numerous long lunches; as well as participants at the Gothenburg Workshop in Political Theory and Practical Philosophy, 15-16 January 2018 for their encouraging feedback.This research was financially supported by the Research Council of Norway, grant no.213547 The Consensus Paradox: Does agreement impede rational public discourse?1.As is common practice (see e.g.Boettcher 2021; G. Gaus 2009;Quong 2022;Tahzib 2022;Vallier 2016Vallier , 2018;;Wall 2022), we take public reason liberalism to be a general category that accommodates liberals whodespite their differencesendorse some version of the public justification requirement.Accordingly, thinkers such as John Rawls, Gerald Gaus and Jürgen Habermas count as public reason liberals even though they disagree on many other aspects.2. While publicity does not imply acceptability, acceptability implies publicitythat is, one cannot properly accept reasons without having been able to evaluate them.Therefore, the condition of publicity is only necessary for the justification of coercive political rules, while the condition of acceptability is both necessary and sufficient for such justification.However, if the public justification requirement were only conditioned by publicity, it would still be epistemically unreliable (if less so than if conditioned by both publicity and accessibility), since it would prioritize neither the inclusion of true beliefs nor the exclusion of false beliefs.3.An alternative to public reason liberalism, the approach we suggest is compatible with a wide range of positions in political philosophy, for example, liberal perfectionism (Galston 1991;Joseph Raz 1988;Sher 2009;Wall 1998), natural law (Finnis 2011;Wolfe 2006) andutilitarianism (Singer 1993;Hare 1981).4. Since acceptability implies publicity (see footnote 2)that is, one must be able to evaluate reasons properly to accept themwe will occasionally use the concept of acceptability without repeating the element of publicity.5.These non-sceptics would include epistemic democrats (e.g.Landemore 2017), liberal perfectionists (e.g.Galston 1991) and natural law theorists (e.g.Finnis 2011).6.To see the far-reaching implications of this position, assume that a majority of citizens endorse a law on the basis of a religious revelation and, further, that the state adopt the law by a correct voting procedure.On the revised epistemic political liberalism view, the law would be legitimate simply because the voting procedure is reasonable.7. Robert Talisse (2008) has proposed a pragmatist 'social epistemic liberalism' whichby focussing on reason-responsiveness and, consequently, justification of beliefspartly overlaps with our approach, but he also accepts the reasoning behind the public justification requirement.
Hence, even if this version, just like Estlund's, points in the right direction, its reliance on the public justification requirement also implies epistemic trade-offs.Likewise, the convergence viewaccording to which there must be some justification available for a political rule without requiring that the justification must be the same for each citizen (which is stipulated by the consensus view)is a step forward (Gaus and Vallier 2009), but it is nevertheless epistemically unreliable.Since the convergence view implies that the pool of available justifications becomes greater, it mitigates the risk of excluding correct beliefs, butlike both Estlund's and Talisse's approachesinsufficiently addresses the risk of including false beliefs.8.However, this shift by no means implies that the truth is irrelevant, since strong arguments can be assumed to be closer to the truth than weaker ones.This is illustrated by the fact that valid inferenceswhich is a feature of a strong argumentare truth-preserving.9. Of course, few proponents of PRL would deny that strong arguments are relevant for the legitimacy of the justification of political rules.However, by endorsing the public justification requirement, PRL gives interpersonal criteria priority over any epistemic concerns.10.This assumptionthat argumentation aims to establish knowledge, rather than consensus or persuasionalso distinguishes our epistemic approach from deliberative or discourse-theoretic approaches (cf.Eemeren and Grootendorst 2004), but its hands-on tools for assessing the epistemic quality of arguments could also allow public deliberation theory to evaluate the supposed force of the better argument (Azmanova 2010;Friberg-Fernros and Schaffer 2017).11.Of course, arguments from authority have their place: When it is practically unfeasible to assess the substantive positions, it may often be preferable to adduce support for a position from an (epistemic) authority.Moreover, under conditions of epistemic uncertainty, one may have reason to defer to epistemic authorities.When assessing the relative epistemic merits of an argument scheme, one also needs to consider the context in which it is used.
12. For this article, we assume that the context, as in PRL, would be a liberal democratic regime where the fact of reasonable pluralism obtains, and we won't here discuss how our approach works beyond that context.13.Such objections need not imply the rejection of the public justification requirement altogether.14.Even varieties of PRL that are more inclusivist towards religious claims usually judges their permissibility on moral criteria.For instance, Andrew March (2013) argues that public justification should be more inclusive towards religious reasons, on certain policy problems where they help expand the public's moral imagination.The epistemic approach, by contrast, rather allows religious reasons on any issue because any and all justifications can be subjected to epistemic scrutiny.15.To see how people may be able to agree on some aspects of the status of arguments even as they disagree on substantive positions: Even professional philosophers, who are arguably more preoccupied with the soundness of arguments than most people, hardly ever agree about the soundness of specific positions (Bourget and Chalmers 2014), yet few things find such wide agreement among philosophers across cultures and over time as the basic rules of valid reasoning, logical inference and rational argument (cf.Friberg-Fernros and Brommesson 2013, 601f).16.Similarly seeking to move beyond the public justification requirement, Bohman and Richardson (2009) suggest instead a duty of deliberative civility, requiring interlocutors to address one another's reasons forthrightly and open-mindedly.Compatible with theirs, our approach adds epistemic standards by which to assess and revise reasons offered in the process.