2. Collective deliberation: a working definition

During the past decades, much has been written about how collective deliberation should be understood. Yet, a clear and comprehensive account of what it means for groups of individuals to deliberate is still lacking. It is therefore useful to return to the basic applications of the term. To that end, I will take a dictionary definition as my starting point. According to the Merriam–Webster dictionary, the term ‘deliberation’ generally denotes:

1. (1) the act of thinking about or discussing something and deciding carefully: the act of deliberating,

2. (2) a discussion and consideration by a group of persons (such as a jury or legislature) of the reasons for and against a measure.

Only the second part of the definition describes the application of the term to the collective level. However, it is noteworthy that the two definitions attribute a common function to deliberation, whether it concerns a single individual or a group: that of carefully examining an issue before reaching a resolution. Just as an individual reflects on their options before making up her mind, a group engages in discussion and analysis of an issue before arriving at a collective position. So, collective deliberation can be understood as a cognitive activity (‘act of thinking’) undertaken by a group of individuals, involving communication (‘discussion’) and reflection through interactive argumentation (‘consideration … of the reasons for and against’) before adopting a position on a common question.

The first element one should retain from the above definition is that collective deliberation requires communication. Communication does not need to include face-to-face interaction but could take place in some virtual space, such as an internet forum. At this point, it is possible to distinguish between interpersonal and diffused deliberation (Landemore Reference Landemore2017, 91). While interpersonal deliberation is held between individuals who are somehow in each other’s presence, diffused deliberation is distributed across a network of agents, such as an international environmentalist network or the governance mechanisms of the State.

For deliberation to be collective though, it is necessary to assume some form of exchange or reciprocity in communication. More precisely, reasons must be presented for and against propositions to facilitate a collective evaluation of the issue at hand. If, on the other hand, individuals solely deliberate within themselves – as a reaction to a public speech, for example – we may have simultaneous individual deliberation but not a collective one. Although collective deliberation does indeed imply mutual communication, this communication need not always be public or evenly distributed. Deliberation may proceed by public, private, or semi-private communicative acts. In other words, messages may be shared with the whole group or addressed to a single agent or to a group of them. It is not always necessary to disclose all information, nor does collective deliberation require that each participant take a turn or express their opinion. After all, participants do not necessarily have the same ability to debate in public or on all possible matters. Some of them may participate as simple listeners.

Yet, a casual discussion among friends about French wines is unlikely to qualify as collective deliberation. Collective deliberation is characterized by a shared focus on resolving a common issue. It can thus be understood as a concerted effort to address a shared question. A question, be it practical or theoretical, sets a choice situation among possible answers (Hamblin Reference Hamblin1973, 48). It is with respect to this question that the premises and conclusion of our reasoning, or the claims and propositions expressed during deliberation, become intelligible (Collingwood Reference Collingwood, Boucher and Smith2013).

However, not all types of questions require deliberation (Wheatley Reference Wheatley1955). If, for example, the question is about what time the train from Paris arrives in Lyon, participants simply need to gather information and respond with an assertion: ‘The train from Paris arrives at 15:30’. Such an assertion is true or false based on the state of the world. In such cases, once the group has access to the relevant information, there is no room for deliberation. What sets deliberative questions apart is their underdetermination with respect to truth considerations (Faure Reference Faure2012). Deliberation is necessary when multiple permissible solutions exist, and no clear, objective method can determine the choice among them. Even if we are confident that all relevant information is available, doubt and hesitation may persist. This is why deliberative questions are typically settled by confronting reasons for and against a decision, hypothesis, or claim. In other words, deliberative questions prompt individuals to evaluate the merits of different options through argumentation. Sometimes, such questions are settled by new information that becomes available through discussion or by appealing to a moral principle or a social convention. However, the very act of submitting an issue to deliberation suggests that reasonable disagreement is likely to prevail.

Deliberative questions give rise to collective deliberation when they require a collective response. Collective deliberation does not merely aim at changing individuals’ minds. It is a goal-oriented activity, embedded in a decision or judgment-making process on the part of a group. Individuals engage in deliberation to figure out what position they will adopt as a group regarding an issue. In this sense, the results of collective deliberation have the property of restricting the space of actions or judgments available to the members of the group. This does not mean that collective deliberation is necessarily conclusive. Further deliberations or the implementation of a decision rule, such as majority voting, are often required to determine the result.

These remarks support the claim that collective deliberation is a form of shared reasoning on the part of a group. Indeed, collective deliberation is generally understood in a way that is inseparable from reasoning. A process of mutual communication is deliberative to the extent that reasoning is used to gather and evaluate reasons for and against alternative options (Landemore and Mercier Reference Landemore and Mercier2012). Whether it concerns scientific inquiry and explanation, everyday conundrums, or complicated political decisions, reasoning is used to improve awareness and examine alternatives set by a common question.

The problem is that reasoning is commonly understood as a cognitive activity on the part of an agent on the content of her conscious attitudes (Broome Reference Broome2013, 234). This raises the question of whether and under what conditions groups reason. Moreover, if deliberation is to be conceived of as a reasoning process, it is necessary to determine the kind of questions it is meant to resolve, as well as its goals. Do groups engage in deliberation to answer questions about what to do, or does deliberation apply to theoretical questions as well? These are the issues I seek to address in the following two sections.

3. The possibility of collective deliberation

Collective deliberation can be described as a form of reasoning on the part of a group. But in what sense do groups reason? Reasoning is something agents do. It is a self-reflective activity, an operation on one’s conscious attitudes, aiming at improving her beliefs or policing her decisions. However, this would require that the group possesses a distinctive set of group attitudes on which it could reflect and act. Deliberating groups can hardly qualify for this sort of agency. Participants in deliberation, even if they do share some common ground, do not have the same reasons for participating, neither do they share the same values or beliefs. On the contrary, this is the reason why collective deliberation is required. How is it possible for groups to reason then?

Reasoning is not an automatic process, but a conscious, intentional activity and, in the case of collective deliberation, a shared intentional activity.Footnote ² Moreover, as I have already explained, collective deliberation is a goal-oriented activity, aiming at reaching a collective resolution. Collective deliberation is thus embedded in a shared intention in at least two ways. For this reason, the possibility of collective deliberation needs to be addressed in terms of what it means for individuals to share an intention. In this perspective, I will draw on Bratman’s account of shared intention and shared deliberation (Bratman Reference Bratman2000; Reference Bratman2004; Reference Bratman2014).

According to Bratman (Bratman Reference Bratman2014), shared intentions are not attitudes in individual minds – urging each individual to do her part in the collective activity, nor attitudes belonging to a collective super-mind. A shared intention should rather be understood as a web of individual attitudes appropriately interconnected. To explain this, Bratman relies on his planning theory of intention (Bratman Reference Bratman2000). He suggests that intentions should be understood as plan states, akin to those involved in the ordinary cross-time organization of action. Plans represent practical commitments that are quite stable but typically partial – that is, they do not yet include the necessary steps to action and need to be ‘filled in’ as time goes by. As such, they structure practical deliberation, by disposing individuals to filter out options perceived as inconsistent with their plans. This function of plans is achieved through the (implicit) acceptance of some norms of intention rationality, the more salient of which are means-end coherence and consistency.

In a shared intentional activity, participatory intentions should be understood as ordinary individual intentions (or plans), that, when applied to actions involving multiple participants, take the form ‘I intend that we J’ (Bratman Reference Bratman2000). This does not mean that I intend to do my part in our joint J-ing. It merely means that I have this plan of acting with you in a certain way and, if you also intend so, we shall both be set to track and support our joint action and filter out options incompatible with this intention – given the norms of intention rationality.

Sharing a goal is thus not enough to guarantee shared intentional action. Participatory intentions should also be appropriately interrelated. More precisely, they need to be interdependent in persistence and efficiency. I will continue to intend that we J, as long as you do as well. Moreover, in shared action, intentions do not simply accidentally coincide, but they are collectively effective. Each intends that we J by way of the intention of the other that we do so. This also means that threatening or forcing someone to participate in the activity would baffle the shared intentional character of the action.

Bratman suggests another condition, which seems central to the understanding of collective deliberation. Imagine that we share the intention that we paint the room. However, I plan to paint it purple, while you plan to paint it beige. In this case, it seems that we don’t really intend that we paint the room (Bratman Reference Bratman2000, 122). Individuals may share a plan to act together in a certain way, but they disagree on how to carry out this action. In this case, for there to be a shared intentional activity, participants need to somehow accomplish ‘mesh’ in their subplans. In other words, their attitudes regarding the shared activity need to be rationally responsive to those of others and seek ways to become mutually satisfiable and socially consistent. Shared intention enjoins us to consider the reasons of others as exerting rational pressure on our reasoning.

Given these remarks, let me examine how collective deliberation can be modelled as shared reasoning. Collective deliberation is part of an overall shared intentional activity on the part of the group. Individuals share an intention that they act together, but they might disagree about how to carry out their joint action. So, they engage in some form of reasoning to specify the means by which they are supposed to ‘fill in’ this plan. The overall shared intention frames collective deliberation in two ways: by setting the question collective deliberation is meant to resolve and by restricting the claims to be advanced. Imagine that members of a municipality share a plan to build a public gym. Given this plan, deliberation is set to identify which are the appropriate means of carrying out this action (e.g., where to build it, what funds to invest, etc.). Moreover, given consistency requirements, participants are set to dismiss plans that go against the shared intention. Claims against building a public gym, and building a department store instead, are rationally excluded from their deliberation. Of course, through this process, individuals might eventually reconsider their shared intention and, sometimes, deliberations break down or do take a different direction. But if we continue so to intend, our joint reasoning will be framed by our shared intention.

Moreover, collective deliberation is itself a shared intentional activity on the part of the group and implies a relevant shared intention, having normative force on individuals’ reasoning. More precisely, collective deliberation is guided by a shared intention of tracking and supporting joint action by means of meshing individual subplans. This condition may be understood in a stronger or weaker sense. On one hand, it is possible to interpret mesh as implying convergence in judgments. According to this perspective, for shared intentional action to be possible, reasons supporting this action should eventually or ideally converge. Indeed, collective deliberation is often understood as aiming at consensus (Elster Reference Elster, Bohman and Rehg2003).

On the other hand, this assumption is highly demanding. Convergence in reasons is neither sufficient nor necessary for shared intentional action. There may be consensus regarding background reasons, without agreement on what to do. For instance, we might all agree on the effects of some new industrial development on the environment and yet disagree as to whether this consideration should be given more weight than that of the profits expected from it (List Reference List2002). It is also possible that individuals agree on some course of action, despite diverging background reasons. There are cases of ‘spurious unanimity’ (Mongin Reference Mongin2016), where a shared intention results from opposing background reasons. A business board might agree on an increase in workers’ wages, while each member endorses this decision for different reasons: some might believe that higher wages increase productivity, others can be motivated by socialist political ideals, while others might think that there is a moral obligation to help others.

Collective deliberation as a shared intentional activity requires each to be responsive to others’ reasons, but reasons invoked during deliberation need not be accepted by all. Still, one might think that there should be some constraints on the kind of reasons that could be admitted during shared reasoning. Shared reasoning is a shared intentional activity guided by a relevant shared intention. This intention enjoins participants to argue towards a common resolution. For that to be possible, there must be some common ground, which, in the context of common knowledge, allows for mutual intelligibility and justifiability. In other words, individuals need to share some common ground, allowing them to collectively understand and appreciate reasons advanced during their deliberation (Bratman Reference Bratman2014).

Once again, this common ground, structuring and making shared reasoning possible, does not imply convergence of value judgments or beliefs. It is a too demanding assumption to think that deliberation is only possible among individuals of the same mind. Parliaments manage to deliberate about different projects of law, even if deputies from competing parties often find each other’s values repulsive (Roth Reference Roth and Zalta2017). So, this common ground should correspond to a thinner form of sociality. Since deliberation is itself a shared intentional activity, it should be conceived of as some kind of preexisting mesh in individuals’ subplans. Common ground is thus this web of interdependent and interlocking participatory intentions regarding some matter, which take the form of shared policies about weights – that is, shared commitments to treat certain considerations as mattering in our shared reasoning (Bratman Reference Bratman2014). For instance, members of a committee deliberating on AIDS prevention policies share an intention to privilege medical considerations and block considerations of – for example – religious nature. Shared policies about weights might appeal to common judgments, but this is not a necessary condition. They may sometimes serve to screen out considerations based on consensual forms of judgment from our shared reasoning (Bratman Reference Bratman2014, 136).

It is noteworthy that shared policies about weights are not mere ‘coordination devices.’ While they may indeed reveal convergence points, their role in shared reasoning is not simply instrumental. They somehow represent the standpoint of the group on a matter (Bratman Reference Bratman2014, 141), according to which claims are to be justified. Indeed, these commitments may be the result of prior deliberation, of common past or cultural background, or of some shared understanding of what it means to be a member of the group. They may often represent some form of modus vivendi, which allows individuals to reason together, despite differences in background judgments and reasons for participating in the process. Of course, these policies are like plans, typically partial and general. So, they are often revisable and defeasible. However, they grant the group some partial but substantial unity that structures and makes shared reasoning possible.

4. The goals of collective deliberation

Following the above, it is possible to define collective deliberation as shared reasoning: Collective deliberation is a shared intentional activity, implying communication and reflection through argumentation against a background of shared policies about weights, with a view to joint action. Aiming at joint action, collective deliberation appears as some form of practical reasoning. But are deliberative questions strictly restricted to questions about action? In epistemic contexts (e.g., within a scientific committee seeking to validate a hypothesis), common questions are also likely to give rise to reasonable disagreement. In such cases, individuals need to formulate reasons for and against positions and judgments to determine what to accept. Moreover, there are cases in which deliberation is required to address axiological questions regarding the goals and priorities of the group. Such communicative interactions that do not involve or do not aim at decision-making, but during which individuals try to collectively make up their minds through argumentation, can they count as instances of collective deliberation?

It is Aristotle (Barnes Reference Barnes1984) who was the first to restrict deliberation to questions about action. Indeed, Aristotle defines deliberation by excluding the things one cannot reasonably deliberate about: one cannot deliberate about necessary things (e.g., mathematical truths), events of the physical world, things that come about by luck, and human affairs that are beyond one’s control. In other words, deliberation applies to objects that are contingent and are up to us to change – typically, questions about action. Aristotle employs the same analysis for collective deliberation. In his treatise on rhetoric (Barnes Reference Barnes1984), he defines collective deliberation as a discourse type reserved for assemblies addressing questions of future action. Using persuasive discourse, participants weigh reasons for and against different courses of action in order to determine the means that contribute to the ends they pursue. The difference between individual and collective deliberation is that the latter implies communication and the existence of the political community – that is, according to Aristotle, common ends.

Since Aristotle, philosophers seem to admit a similar distinction between practical and theoretical reasoning – generally, reserving the term ‘deliberation’ to the first. They argue that our actions are (at least sometimes) the result of a type of reasoning – practical reasoning – and that this type of reasoning is to be distinguished from reasoning about what to believe – theoretical reasoning – with respect to both its subject matter and its norms. Practical reasoning begins with a normative question about what to do: Should we take the train or drive to Paris? There might be equally good reasons to choose to go by train or by car. To answer such questions – to decide – we need to consider and weigh the reasons for and against each option and figure out which one is the most worth choosing. Reasons admitted in practical reasoning may be pragmatic or idiosyncratic, and the answers to practical questions – decisions – depend on how important these reasons are for each of us in the situation.

By contrast, the goal of theoretical reasoning is not to tell us what to do, but what to believe. The result should thus be a new belief or a reinstatement of one we already have. Contrary to practical questions, regarding which we are free to make up our minds, theoretical questions about how the world is, are rationally settled compulsorily – by reference to agent- and context-independent criteria, namely evidence and proof. It seems to be an abuse of language to say that, after performing a pH test, I decided that some liquid is acid (Wheatley Reference Wheatley1955). Wishful thinking and self-deception – that is, justification of beliefs by practical reasons – are dismissed as irrational behaviours.

According to this analysis, only practical questions – that is, questions that are generally resolved by a decision – are deliberative ones. However, is deliberation always irrelevant when it comes to theoretical questions? First of all, one might notice that certain theoretical matters engage practical considerations. Often enough, pragmatic pressures, having mainly to do with time and resources, might play an important role in judgment. Indeed, scientific advisory committees established during the COVID pandemic had to make decisions based on partial evidence and ongoing research. In such cases, suspending judgment is not a sustainable policy and a decision about how the world is seems necessary.

One could set aside such hybrid cases and focus on a purely epistemic setting, such as scientists in a research team trying to validate a common hypothesis. Even in such a context, deliberation might have an important role to play. This becomes particularly obvious when we consider cases of disagreement among epistemic peers – that is, individuals among whom no one has a clear epistemic advantage. The question is then how disagreement over factual matters can persist without being able to discount anyone’s judgment by appealing to genuinely epistemic reasons, such as considerations of intelligence or ignorance of relevant evidence (Kelly Reference Kelly, Szab´o Gendler and Hawthorne2005). If reasonable epistemic disagreement is possible, theoretical questions can also involve deliberative issues, which cannot be resolved using ‘independent checks’ (McGrath Reference McGrath and Shafer-Landau2008, 97).

Indeed, a single phenomenon may allow for more than one permissible explanation. The choice among them cannot generally be settled by considering the available evidence, including higher-order evidence about each other’s expertise. Non-factual disagreements, which cannot be objectively resolved, are not uncommon in science. These disagreements often stem from foundational and methodological differences among scientists (Weinberger and Bradley Reference Weinberger and Bradley2020), particularly as the complexity of the subject and the level of uncertainty increase. Methodological pluralism, for instance, can lead to disagreement about the relative merits of one another’s evidence (Dang Reference Dang2019). Even when there is agreement on the evidence gathered, disagreements may persist about what can reasonably be inferred from it (Longino Reference Longino1979). At any given time, the available evidence may be insufficient to determine which beliefs the group should adopt (the underdetermination thesis), or the same body of evidence may equally support competing doxastic attitudes toward the same proposition (the permissivism thesis). Finally, suppose the group resolves these issues and reaches a conclusion. It may still be the case that the conclusion drawn from the evidence requires a massive revision or contraction of other beliefs. In such circumstances, group members might disagree on whether to accept the conclusion or instead consider the likelihood of future evidence. Disagreement in this last case is exacerbated when scientific results are meant to inform public policy – as, for instance, the assessment of uncertainties in the Intergovernmental Panel on Climate Change (IPCC).

Collective deliberation is not restricted to practical questions. Theoretical questions are quite often deliberative ones, to the extent that they cannot always be resolved by appealing to independent criteria of truth but need to be submitted to discussion and argumentation. This is compatible with my previous analysis of deliberation as shared reasoning. Epistemic deliberation is itself a shared intentional activity: it is guided by a relevant shared intention – that of handling uncertainty and disagreement by means of responsiveness to others’ reasons. It is also embedded in an overall shared intentional activity on the part of the group – that of scientific inquiry and explanation. Moreover, scientific deliberation takes place against a common epistemological ground, which determines justifiability in a scientific context.

Whether it concerns a group making a decision or forming a judgment, collective deliberation has so far been presented as a goal-oriented activity. Collective deliberation is embedded in an overall shared intentional activity on the part of a group. But what about social contexts of communicative interaction where reasoning in common occurs, specific questions are addressed, yet the aim is not directly to produce or conclude with a decision? This class of exchanges, generally seeking to produce evaluations or recommendations, includes debates among a panel of experts preparing an assessment report, within a feminist assembly addressing policies against domestic violence, or among citizens participating in a deliberative poll (Fishkin Reference Fishkin1992). Can these exchanges be considered deliberative, and if so, in what sense?

Axiological debates, aiming at evaluating alternatives or setting goals and priorities, are a crucial part of most deliberations since axiological disagreement is the deepest form of disagreement that individuals need to address during their decision-making. Nevertheless, an evaluation is not a decision: One may, for instance, judge that A is better than B and remain undecided. There are also weak-willed intentions that are contrary to any thoughtful evaluation (Bratman Reference Bratman2014, 19). Akrasia may as well be collective. Game theory offers us paradigmatic analyses of such cases, where, while individuals do see the optimal choice, they often agree on the second-best one.

While it is true that an evaluation does not amount to joint action, it is still possible to describe axiological debates as a particular form of theoretical deliberation. The result could then be interpreted as a common judgment on some evaluative matter. Yet, axiological debates still do not conform to our understanding of collective deliberation as shared reasoning. The problem is that the result of axiological debates does not need to be relevant to the group’s future behaviour. In other words, axiological debates are not necessarily embedded in a shared intention. Scientific deliberations have been understood with respect to their role in resolving questions regarding joint scientific inquiry and research activity. Consider, on the other hand, a students’ assembly discussing possible democratic reforms – a matter that largely exceeds the assembly’s authority. If the participants do indeed come up with a common judgment, this judgment does not engage the group in any possible way. If deliberation is to be extended to apply to any discussion ending up with a common opinion, it would be difficult to distinguish collective deliberation from mere conversations.

So, under what conditions can axiological debates qualify as deliberative ones? To respond to this question, I will return to Bratman’s planning theory of intention (Bratman Reference Bratman2000). As I have already explained, groups’, as well as individuals’, planning activity is structured by partial plans – that is, practical commitments that, while being relatively stable, they do not yet include the necessary steps to action. Collective deliberation is needed to ‘fill in’ the group’s plan to act in a certain way. Thus, axiological deliberations could be interpreted as concluding in a partial plan, which should be then filled in by further deliberations. Hence, it is possible to distinguish three different types of axiological debates: binding deliberations, consultative deliberations, and mere conversations.

Binding deliberations refer to those held by a group empowered to make decisions. They are typically followed by the application of a decision rule, which determines the collective outcome. For instance, when a business board deliberates on the commercial goals for the upcoming semester, the conclusion carries executive authority – it is an evaluation that directly impacts the group’s actions. Consultative deliberations, on the other hand, do not directly aim to produce binding conclusions. However, these interactions are deliberative insofar as they form part of a broader decision-making process. They are designed to define a partial plan, which, while not immediately constraining the group’s actions, serves to guide further deliberations and decisions. For example, deliberations within a Clinical Ethics Committee are meant to resolve ethical issues raised by medical practice within the hospital, which, after being reviewed by the relevant administrative bodies, help shape the regulations governing practitioners’ activities. Finally, one can distinguish the above deliberative interactions from mere conversations. The latter do not qualify as deliberative, as their outcome does not commit the group to any specific course of action, nor do they appear to influence a larger decision-making process.

5. An explication of collective deliberation

In the previous sections, I have proposed an explication of collective deliberation as shared reasoning, that it is now possible to formulate more precisely. An interaction is an instance of collective deliberation if and only if:

1. (1) It can be described as shared reasoning – that is, a reflective activity on the part of the group regarding some common question, involving mutual communication and collective assessment of possibilities.

2. (2) Shared reasoning is an intentional activity on the part of the group, that embedded itself in an overall shared intentional activity and is performed against a background of interrelated shared intentions – shared policies about weights – which correspond to the standpoint of the group.

3. (3) Shared reasoning aims at resolving deliberative questions – that is, questions, that are not distinguished by their subject matter (i.e., theoretical, practical, axiological), but by the fact that they are likely to give rise to disagreement that cannot be independently tracked.

Building on Carnap’s account of explication (Carnap Reference Carnap1971), I have taken as a starting point the ordinary uses of the term ‘collective deliberation’ (explicandum) in decision and judgment making and attempted to propose a more precise concept (explicatum). In this last section, I assess the proposed concept according to Carnap’s criteria of theoretical adequacy. Following Carnap, an explication is successful as long as it satisfies to ‘a sufficient degree’ four desiderata: simplicity, similarity, exactness, and fruitfulness (Carnap Reference Carnap1971, 7). In what follows, I rely on Carnap’s account, while adopting a more permissive interpretation of the above criteria.

The concept of collective deliberation as shared reasoning is simpler than other potential alternatives and conceptual elaborations in philosophy and social sciences. The analysis of shared reasoning, based on Bratman’s account of shared agency, admits the least possible assumptions on the ground level of explanation. This contrasts with normative accounts of shared intention – in particular, the obligation-based account proposed by Gilbert (Gilbert Reference Gilbert2009).Footnote ³ Moreover, the concept of collective deliberation as shared reasoning makes no assumptions concerning the quality or the rationality of the deliberative process, contrary to some normative understanding of collective deliberation, inspired by Habermas’ logic of communicative action (Habermas Reference Habermas1984). These approaches enable an evaluative-descriptive understanding of collective deliberation – that is, deliberation is described in a way that is inherently approbative (Skinner Reference Skinner1974). Although collective deliberation indeed has some positive connotations – decisions are likely to be better if we take the time to reflect on them – these potential positive effects are not inherent to the concept.Footnote ⁴

A second desideratum the explicatum should satisfy is similarity. According to Carnap, ‘[t]he explicatum is to be similar to the explicandum in such a way that, in most cases in which the explicandum has so far been used, the explicatum can be used; however, close similarity is not required, and considerable differences are permitted’ (Carnap Reference Carnap1971, 7). Hence, similarity does not mean descriptive accuracy – explication always involves a part of idealization and abstraction. What is nevertheless necessary is that the new concept captures the main uses of the term in our common practice.

One might object that some rather common deliberative situations fall out of the concept of collective deliberation as shared reasoning. Collective deliberation has been understood as aiming at resolving – typically through argumentation – questions that are likely to give rise to disagreement. However, in practice, issues submitted to deliberation are often settled in an objective and unanimous way, without any need to argue. For example, juries engage in deliberation at the issue of the trial to determine the defendant’s guilt. Often enough, the decision is obvious given the evidence presented in court. This does not dismiss the fact that such decisions require deliberation because the jury needs to establish that the defendant is guilty ‘beyond reasonable doubt’. This instruction enjoins the members of the jury to assess the relevant evidence (or the lack of it), to compare it, and, in the absence of absolute certainty, to reach a reasonable judgment.

A third and rather central requirement the explicatum should satisfy is exactness. Exactness requires that the rules governing the use of the new concept are precisely formulated. This is essential for distinguishing the frontiers of the concept. The concept of collective deliberation as shared reasoning establishes criteria for making the difference between collective deliberation and other communicative interactions. It becomes clear that deliberation differs from a simple discussion or an argumentative debate since the latter are not embedded in a shared intentional activity.

What is less obvious and needs further explanation is the distinction between collective deliberation and bargaining. On one hand, bargaining looks a lot like shared reasoning (Westlund Reference Westlund2009). Bargaining does not merely aim at coordinating separate individual intentions but is guided by an overall shared intention (e.g., the distribution of some benefit). Furthermore, bargaining is itself a shared intentional activity since participants jointly seek to reach a mutually acceptable (and sometimes mutually beneficial) agreement. As such, it presupposes some common background commitments, without which the interaction would not be possible. Some simple rules of conduct are generally implied, such as refraining from using physical violence. On the other hand, collective deliberation and bargaining are not essentially different regarding the motivation of the participants. Deliberative questions, as well as bargaining ones, often involve distributive issues. Collective deliberation does not exclude the possibility that, in attempting to secure a better position for themselves, participants strategically withhold information or misrepresent their reasons.

What distinguishes collective deliberation from bargaining? While both entail reasoning by two or more individuals in response to a common issue, the nature of reasoning in bargaining, though interdependent, is not shared (Westlund Reference Westlund2009). Individuals are set to track a mutual agreement by reasoning individually about what the other parties might accept. Collective deliberation, on the other hand, requires that claims are justified according to what can count as a reason for the group. Indeed, collective deliberation appeals to a common ground of shared policies about weights, which restricts the type of reasons that can be advanced during argumentation. Hence, the aim of collective deliberation as shared reasoning is not simply to come up with a result acceptable to all but with a result that is justified given the standpoint of the group.

By defining clear frontiers to a concept, exactness seems to be at the core of the fourth, and probably the most important, desideratum of an adequate explication – namely, theoretical fruitfulness. Fruitfulness describes the explication’s goal to enable knowledge production about the phenomena to which the explicandum pertains (Dutilh-Novaes and Reck Reference Dutilh Novaes and Reck2017). The proposed concept of collective deliberation can contribute to a better understanding of the mechanisms of collective deliberation and its potential effects.

Empirical investigation would benefit from a clear definition of collective deliberation. Indeed, empirical research regarding the effects of collective deliberation tends to support conflicting conclusions. For example, Fishkin’s experiments on deliberative polls (Fishkin Reference Fishkin1992) are frequently used to argue for the positive epistemic effects of deliberation (Farrar et al. Reference Farrar, Fishkin, Green, List, Lushkin and Levy Paluck2010). These polls, conducted before and after discussions and participants’ exposure to information and experts’ opinions, suggest that collective deliberation improves individuals’ independent judgments. In contrast, based on a different type of experiments, Sunstein argues that deliberation is often ineffective in improving the group’s judgment, amplifying individual errors instead of correcting them (Sunstein Reference Sunstein2006, 14).

Despite the undeniable value of these studies, they fail to provide robust results regarding the effects of collective deliberation. Each focuses on particular aspects of the interaction while neglecting other critical dimensions. Fishkin’s experiments emphasize the reflective and argumentative element of the interaction while overlooking the fact that collective deliberation is a goal-oriented activity.Footnote ⁵ Yet, individuals may remain opinionated or polarized in a decision-making context. Conversely, Sunstein focuses on the goal of deliberation to produce collective outcomes but narrowly construes it as a method of eliciting and aggregating information (Sunstein Reference Sunstein2006: 7). This approach prevents him from distinguishing collective deliberation from other forms of communicative interaction. Contrary to the experimental settings he refers to, collective deliberation is not analogous to the kind of reasoning used to estimate the number of beans in a jar or the response to quiz questions. Rather, collective deliberation involves the group collectively evaluating alternative reasonable solutions by weighing reasons.

Without a clear and general definition, theoretical debates risk becoming fragmented, and empirical studies lack the consistency needed for meaningful comparison. A shared definition ensures that researchers address the same phenomenon while laying the groundwork for formalization. This not only enables rigorous interdisciplinary theorizing but also facilitates institutional design, fostering the development and refinement of deliberative institutions that effectively support collective reasoning and decision-making.

Some may object, however, that collective deliberation resists a universal definition, arguing that its norms, goals, and practices are context-dependent, varying across cultures and institutional settings. Furthermore, collective deliberation encompasses a variety of reasoning and discourse practices (e.g., argumentation, information sharing, narratives), as well as diverse group dynamics. Consequently, any attempt at a universal definition might overlook the richness and diversity of collective deliberation as it occurs in practice.Footnote ⁶ While this objection highlights the complexity of the phenomenon, it also underscores the risk of undermining conceptual clarity, which is essential for scientific inquiry. Despite this diversity, I have argued that certain underlying conditions – such as shared reasoning, mutual communication, and the weighing of reasons – remain consistent when thinking of collective deliberation. By identifying these core necessary and sufficient conditions, the concept of collective deliberation as shared reasoning offers a unifying framework that allows for flexibility and adaptation without sacrificing conceptual clarity.

The concept of collective deliberation as shared reasoning offers a simple yet plausible way of distinguishing key features of collective deliberation. It helps dismiss common misunderstandings and seems to contribute to fruitful theorizing about collective deliberation both in philosophy and social sciences. Thus, it is likely to guide theoretical elaboration and enhance measurability, testability, and theoretical unification.