What is the Point of Solidarity?

I. INTRODUCTION

Of all the theories for why some revolutions that should have happened didn’t, perhaps this is the simplest one: all would-be revolutionaries had other things to do. There are work projects to finish, department meetings to attend, clients to keep happy. More importantly, there are families to care for, old friends to be in touch with, books to be written. These things (at least those in the latter sentence) don’t just appear important to us. They really are important, providing reasons that are, though personal or agent-relative, still objective, weighty, and frequently duty-grounding. Yet tragically, they conflict with heading to the barricades right now.

This article proposes that we understand the social practice of solidarity as a response to this fundamental human predicament; and doing so sheds light on features of solidarity that philosophers have struggled to make sense of. On the view this article advances, solidarity responds to a basic need that people like us have in a world characterized by sharp and persisting injustices: by structuring (some of) our personal projects in line with (and in the service of) our general moral duties, we can, to some extent, reconcile our pursuit of such personal projects with these general moral reasons. And by standing with others in shared struggle, we simultaneously respond to demands of justice and act on our personal reasons stemming from our need to share in valuable relationships. Thus, I argue that committing to particular others and particular struggles in light of who we are—and aspire to be—helps us to promote justice without adopting an alienating conception of ourselves as mere instruments for the realization of some abstract normative goal or principle. In a slogan: “solidarity makes justice personal.”¹ I claim that this is the most fundamental, positive alignment function that solidarity practices serve. While there are alternative ways of aligning our ethical life with our general moral reasons and duties (think: charity and pure altruism) alignment can give rise to more or less valuable bonds to other people. I maintain that solidarity is the practice that brings about positive alignment by forming distinctly valuable relationships with one’s comrades in solidarity, thus serving a human need to stand in such relations with others.

There exists at present a significant gap between theory and practice when it comes to solidarity. Those fighting for social and humanitarian causes—whether Black Lives Matter protesters,² #MeToo activists,³ or those who fought to contain the Covid-19 pandemic⁴—often attach great importance to the ideal of solidarity, couching calls for mobilization and support in terms of it. By contrast, analytic political philosophy has only recently started to pay close attention to the ideal. The aim of this article is to present an account of solidarity that connects it to existing practices, yet also vindicates it as a theoretically useful and distinctive ideal for moral and political theorizing.

But doing so, I will argue, requires a methodological shift. A natural and thus far dominant way of approaching solidarity as a philosophical topic starts with setting up necessary and sufficient conditions of what the concept is a concept of, or what it designates. It is only after we have addressed the conceptual question that we turn to the justificatory challenge, asking such questions as when solidarity is permitted or required, what social groups must be like to ground duties of solidarity,⁵ and what makes solidarity valuable (when it is valuable).⁶ Following recent work on complex social phenomena like knowledge, trust, and blame,⁷ the strategy pursued in this article reverses this order: starting with the functional question, “What is the point of solidarity?,” and laying out core needs to which solidarity practices answer, I delineate the conceptual space of solidarity by reference to its normative functions. Doing so helps to better understand, if not to resolve, a number of disagreements within the existing literature. More importantly, it assigns an attractive and unique normative phenomenon, and one for which we presently lack a clear term, to the ideal of solidarity and explains its inner logic.

My plan is this. Section II locates solidarity by first setting out a few general assumptions about solidarity that are commonplace in the literature. I then sketch, in Section III, some central disagreements and puzzles about solidarity’s nature, value and deontic status. Section IV describes the human need to which our practice responds, to wit, the need to reduce the tension that exists between our responsibility to address impersonal demands of morality and the responsibility to lead a fulfilling life that contains valuable projects and interpersonal bonds. In Section V, I demonstrate how solidarity helps to address this need in a unique way through what I call positive alignment between personal projects and moral demands. I then show how the same mechanism works in relation to aligning general moral demands with our need to stand in valuable relationships. Section VI describes how the attributed function illuminates some of the central disputes about solidarity’s nature. Section VII turns to the puzzles about solidarity’s value and deontic status, explaining how a functionalist account provides a convincing explanation of both. Section VIII concludes.

II. LOCATING SOLIDARITY: CORE CHARACTERISTICS

Philosophers writing on solidarity frequently start with examples that they consider paradigmatic and then rely on these to identify necessary and sufficient conditions for something being an instance of solidarity. I propose to approach solidarity differently. Instead of trying to list individually necessary and jointly sufficient criteria, my initial aim is to collect features generally attributed to solidarity. Only after this general characterization will some examples that have many, but not necessarily all, of these features be used to reveal solidarity’s point.

By way of background, I assume—uncontroversially, I hope—that solidarity designates a practice, that is, a human activity governed by certain norms that are partly constitutive of the activity. One basic feature of solidarity is that it is a social practice: the activity under scrutiny is directed towards others (one cannot be in solidarity with oneself). But while activities like imitating or threatening too are social in a superficial sense, solidarity is social in a deeper sense: it is a practice governed by a relational ideal. So solidarity, in my usage, designates a practice fundamentally governed by an ideal: the practice consists in the socially embedded enactments, attitudes, and behaviors, while the ideal designates the interrelated set of values that explains why participants have reason to care about this practice.⁸ Explaining the practice of solidarity thus consists (at least in part) in describing the application conditions of this ideal, uncovering its distinctive content, and revealing why its features are what they are. Specifically, I want to draw attention to four core characteristics and show how, in combination, they render solidarity different from other, perhaps more familiar, ideals (and their corresponding practices). While these characteristics are broadly acknowledged in the literature, they also, individually and jointly, give rise to disagreements and puzzles that I will describe.

III. DISAGREEMENTS AND PUZZLES

Despite a recent surge in philosophical interest in solidarity, there remain deep philosophical disagreements and significant puzzlement about the practice. These can be located at three levels: in relation to solidarity’s nature, its value, and its deontic status.

Solidarity’s nature. Despite the widely shared assumptions about solidarity’s core characteristics just listed, there is not even agreement among theorists about what solidarity, fundamentally, is. Some—call them minimalists—think that being in solidarity can require little more than a stable desire (e.g., for unity) and an intention (e.g., to accept costs to realize it).²² Others—call them maximalists—hold that “real” solidarity is a complex type of joint action. Maximalists often make highly specific and demanding assumptions: e.g., that solidarity entails mutual identification, shared goals and intentions, mutual trust, and related ideas.²³ Minimalists and maximalists disagree, for example, about whether a silent act of individual sacrifice can be as paradigmatic an instance of solidarity as organised, large-scale political action.

But even among maximalist accounts that tie solidarity to shared agency and joint action, there is little agreement about which features are central and, relatedly, which cases are paradigmatic. Some see external solidarity (“solidarity with”—e.g., where a privileged non-member joins a disadvantaged group in its struggle against oppression) as central, and appeal to the fact that such solidarity requires deference to the disadvantaged as fundamental to the practice.²⁴ Others consider internal solidarity (“solidarity among”—e.g., workers striking together to combat their oppression in the workplace) as more paradigmatic, and see norms of reciprocity and “fate sharing” as solidarity’s conceptual core.²⁵

Solidarity’s value. The fact that solidarity is both cause-mediated and, like love or friendship, contains elements of self-other-integration raises a fundamental puzzle about its value. We often distinguish between purposive and non-purposive relationships. Purposive human relationships, say between a lawyer and her client, are typically instrumentally valuable: they help to secure certain relationship-independent goods. By contrast, non-purposive (or perhaps “open-ended”) relationships, say friendships or romantic life partnerships, are non-instrumentally valuable.²⁶ Solidarity’s value appears ambiguous in that, unlike non-instrumentally valuable open-ended relationships, its value is often taken to depend on the cause that defines it.²⁷ For example, many would deny that solidarity among Nazis or members of the Mafia has non-instrumental value.²⁸ And yet it seems that one would fail to fully satisfy the relational ideal of solidarity if one valued one’s being in solidarity with others exclusively as a means to realizing a cause. Faced with this puzzle, the literature is split between purposive and non-purposive accounts (or “teleological” vs. “loyalty” accounts²⁹) of its value. According to the former, it is the realization of these goals that renders solidarity practices valuable.³⁰ Adherents to such accounts tend to ignore instances of solidarity not aimed at pursuing a goal mandated by justice. By contrast, non-purposive accounts stress how solidarity is partly valuable independently of its aims, for example by constituting a type of community among the oppressed or revealing valuable character traits.³¹

Solidarity’s deontic status. A final puzzle concerns solidarity’s deontic status. Does solidarity give rise to distinctive, novel duties? Our intuitions here seem torn. On the one hand, we can easily think of cases where duties of solidarity seem derivative. Think of co-workers in a strike: here the duties that fall on members of the group, e.g., not to cross the picket line, seem to flow from solidarity-independent obligations, say general duties to fight injustice, or duties of fair play.³² However, in other cases, it is, at least intuitively, precisely the act of committing to a group/cause that gives rise to new moral demands. Think of an outsider committing to a struggle of one among several disadvantaged groups: specific duties here seem to arise from the fact that one has pledged allegiance. And, perhaps like duties of love or friendship, these duties appear grounded more immediately and non-reductively in the interpersonal bonds formed through one’s solidarity engagement.

IV. AN ALTERNATIVE APPROACH: FUNCTIONALISM

I am not the first to remark on these core features of solidarity: nearly every philosophical piece on the topic notes at least some of them and describes how solidarity differs from pure altruism, insurance, group loyalty, and so on. But having noted some of solidarity’s complex characteristics, many commentators adopt a strategy of either exclusion, proliferation, or elimination. Those embarking on the first disregard some features as central, thereby reducing solidarity’s complexity. Those opting for proliferation either drastically widen the scope of what should count as solidarity, often subsuming just about any pro-social behavior or attitude under it,³³ or, alternatively, stipulate various “kinds,” “types,” or “senses” of solidarity, often without accounting in detail for why these are all instances of a unified phenomenon.³⁴ Finally, eliminativists suggest that, once its seemingly conflicting elements are properly defined, solidarity reduces to justice, or community, or some other more familiar concept.³⁵

I find these strategies unsatisfactory: solidarity’s complex internal structure strikes me not as an aberration that a philosophical analysis of solidarity should either ignore or eradicate by conceptual fiat, but as something that such an analysis should explain. Why is there a need for a practice whose motivational requirements can neither be captured fully in terms of the pursuit of self-interest nor in the pursuit of altruistic motives? Why do each of the internal (“solidarity among”) and external (“solidarity with”) cases seem especially paradigmatic to some? Why do both purposive and non-purposive renditions of solidarity’s value seem plausible? And why does it at least appear both that solidarity can be a source of sui generis moral obligations and that some familiar moral obligations can give rise to demands for solidarity?

My suggestion is that we embark on a more ambitious explanatory project that answers these questions by starting from a broadly functionalist perspective. Functionalism pursues the task of explaining a practice through a three-step method. First, we lay out core features of the practice (what I have done above). Second, we formulate a hypothesis about the point of such a practice, by identifying needs or predicaments to which it responds. We then work out this point by dissecting the central (and perhaps unique) functions that the practice serves in addressing these needs or predicaments. One way to think about this is in terms of difference-making: what would be lost if we lacked such a practice in our lives? For example, a social practice may enable beings like us to form and revise attachments to others and create shared understandings regarding wrongdoing. (This is the point of blame, on certain functionalist accounts of it.³⁶) Or it might help us by improving our epistemic position. (This is the point of testimony, on a familiar view.³⁷) My functionalist explanation of solidarity builds on the idea that it is by straddling notions like self- and other-regarding interest, duty and self-realization, etc. that solidarity serves fundamental human needs. Admittedly, this may sound merely suggestive at this point. But the next section will, I hope, explain the functional value of these complex aspects of our practice. ³⁸

The expected benefit of first asking “What is the point of solidarity?” rather than “What counts as solidarity?” is twofold. First, we now have at hand a clearer method for addressing questions about solidarity’s nature. We can order our intuitions about cases by identifying whether and to what degrees its function is realized. Once we have demonstrated how the practice advances our needs in paradigmatic cases of solidarity we can ask whether, and if so how, these functions are also advanced in more controversial cases. More importantly, second, a functionalist explanation of a social practice offers a principled way of “vindicating” our existing practice. A practice is vindicated when reflection on its function reveals reasons for endorsement—that is, when its shape and purpose can be seen to make sense, and remain justifiable, from the perspective of those who engage in it.³⁹ Such vindication seems especially valuable for solidarity, which is often treated reductively, as something whose practical and theoretical value can be fully accounted for in terms of something else, like justice, equality, or community. By working out its point and providing a deeper explanation of its shape, value and deontic status, we can redeem solidarity’s practical and theoretical usefulness.

V. THE FUNCTION OF SOLIDARITY: POSITIVE ALIGNMENT

The suggestion in the previous section was that we can approach the question of a practice’s function in terms of difference-making: what would be lost in our lives if we lacked this practice? We can now sharpen this question for the issue of solidarity: what would be missing in our lives, faced with the conditions I have sketched, if we lacked a practice that has the features described? Pertinent descriptive features of solidarity were (i) unity/fellowship, (ii) will-dependence, (iii) self- and other-interest-integration, and (iv) cause-mediation. We can now ask: what would be missing if we lacked the ability to relate to others in this way?

My answer is that absent such a practice, we would be lacking one crucial way in which we can lessen the force of the predicament characterized by (moral and ethical) failure, estrangement, disaffection, and disempowerment. Solidarity enables us to turn morality-given causes into ones that we have additional personal reasons to pursue in distinctive ways. So, solidarity is centrally the practice of reinforcing agent-neutral (justice- or morality-given) causes by aligning our self-chosen personal (project- and relationships-given) reasons with them. In order to spell out precisely how the practice helps us to lessen the force of the predicament described, I will first precisify my earlier characterization of how solidarity requires engagement of one’s will. We best understand solidarity’s core function if we see it as a distinctive form of attachment that results from a commitment, namely one that responds to reasons stemming from both our moral and our ethical responsibility.

VI. “FORM FOLLOWS FUNCTION”: SOLIDARITY’S NATURE

I now turn to some of the disagreements and puzzles surrounding solidarity noted in Section III. In this section, I focus on the questions of solidarity’s nature. My suggestion is that a functional account provides a helpful and principled way of assessing disagreements concerning solidarity’s core aspects and outer boundaries. For reasons of space, my discussion is not comprehensive, but only points out how the functional idea of positive alignment illuminates central disputes.

Minimalist vs. Maximalist. We noted earlier that there is disagreement about solidarity’s basic form. Test cases here are cases of silent solidarity like Chams’s, where (putative) acts of solidarity do not form part of shared agency. Since there is no reciprocal fate sharing, or mutual trust, or even knowledge of each other between the person acting and the group picked by the cause, maximalists claim that such cases are either not cases of solidarity at all, or, if they are, they constitute much less paradigmatic ones (Andrea Sangiovanni calls them “latent”).⁶² Thinking about solidarity in terms of alignment can help us better understand both the reasons underpinning the minimalist’s affirmative stance and the maximalist’s scepticism about such cases.

Positively, acts of silent solidarity succeed to some extent in creating exclusionary reasons. Once Chams has resolved to support this particular cause, he has engaged in an act of self-authorship that, from his perspective,⁶³ matters and serves the moral goal of standing with the women in Iran. Yet in support of the maximalist’s skepticism, we can note that, first, it is harder to see which distinct agent-neutral moral values exclusively private acts of solidarity are advancing. Secondly, and to my mind more importantly, because silent commitment remains exclusively internal, it fails in the reverse functional purpose of reinforcing the person’s ethical aims through a moral concern. It is, in a way, like an addict picking a sponsor, but then not communicating her decision to that person. The decision itself may have some force in the addict’s sobriety project, but the distinctive additional element that comes with “personalizing” projects through reciprocal interpersonal bonds cannot (yet) succeed.

But doesn’t this vindicate the maximalist position because it makes instances of silent solidarity less paradigmatic than cases where shared intentions, trust, and joint action are present? Not necessarily, or at least not in the sense that all instances of solidarity that satisfy the maximalist requirement for “full” solidarity count as more paradigmatic than all instances of silent solidarity.

On my account, centrality turns on how well an episode advances positive alignment between an agent’s moral and ethical responsibilities. In what we may think of as the “ideal case” of solidarity, an agent’s important moral duties are aligned with important personal reasons and relationships. Cases of solidarity are less central if they deviate from this ideal case in one or another way: if, that is, they advance significant moral obligations, but do not add much to our ethical life, or if they significantly advance our ethical needs but only modestly advance important moral aims. At the extreme, episodes that either completely fail to advance the agent’s moral reasons or completely fail to advance the agent’s ethical reasons barely count as solidarity, if they count at all: bonding together to realize some morally evil end is not a central case of solidarity. And neither are instances of “ultimate sacrifice,” in which an agent heroically gives their life to protect others.⁶⁴

How does this bear on the choice between minimalist and maximalist conceptions of solidarity? It is reasonable to assume that maximalist instances of solidarity, which involved relationships of shared agency, mutual trust, etc., nearly always better meet our ethical needs than merely minimalist instances of solidarity, which do not contain such significant relationships. Consequently, the best cases of maximalist solidarity will be more central than the best cases of minimalist solidarity. Yet it does not follow that every instance of maximalist solidarity is more central than any instance of minimalist solidarity (e.g., Chams’s case of silent solidarity), because centrality depends on both the ethical and the moral responsibilities at stake. Imagine Chams’s silent actions make only a modest contribution to his ethical self-realization but a significant contribution to his moral responsibilities.⁶⁵ Compare this with an instance of maximalist solidarity that, though it makes a significant contribution to the participant’s ethical life, nonetheless only makes a minor contribution to their fulfilling their moral duties. The latter might therefore be less central overall than Chams’s silent solidarity.⁶⁶

Internal vs external solidarity. Another disagreement regarding solidarity’s nature, recall, concerned whether the internal (“solidarity among”) or external (“solidarity with”) variant should count as the central, paradigmatic case. Here too, my functional explanation offers an elegant explanation of what accounts for these differences in assessment and how we might overcome them. A first step is to recall that different constellations can lead to different ways in which we experience a mismatch between ethical and moral responsibilities. For example: when we are already members of a group struggling against oppression, i.e., in instances of internal solidarity, then disempowerment (not knowing how to choose a cause) does not seem an especially pressing problem.⁶⁷ On the other hand, disaffection (feeling that morality’s demands limit one’s ethical self-realization) very well might and is something that our solidarity commitment addresses. Conversely, when—as members of a privileged group confronted by numerous equally pressing injustices—we commit to one specific struggle (“solidarity with”), then solidarity solves a different variant of the alignment problem and can alleviate a different pathology from which we might suffer (disempowerment).

On the functionalist account I propose, the more positive alignment an episode creates, the more paradigmatic an episode of solidarity it is. As a result, there may simply not be a definitive answer to the question which variant is more paradigmatic. Internal and external solidarity each help to address the practical conflict that solidarity targets, even if they each do so in somewhat different ways. Sometimes solidarity reduces the tension between ethical and moral responsibility by ensuring that we avoid disempowerment. Sometimes it helps to avoid estrangement or disaffection. What those suggesting that one or the other of these variants should count as more paradigmatic fail to see is that they each fully realize solidarity’s point.

The role of deference. A further subject of controversy regarding solidarity’s nature concerned the role of deference. Some suggest that one cannot be in solidarity unless one sets aside one’s practical judgment on moral matters relating to some cause, and lets another’s (in particular, the victim’s) judgment guide one’s actions.⁶⁸ For example, if you are a white person in the American South in the 1960s, you are in solidarity with the civil rights movement if you follow the instructions of its leaders, not if you do what you think best advances racial equality. Avery Kolers generalizes from these cases, suggesting that all solidarity is “reason-driven political action on others’ terms.”⁶⁹ And to act on others’ terms is to defer to their practical judgments. Others object: Samuel Dishaw argues that deference seems inimical to one central element of solidarity, namely that those bonding together create a shared moral understanding of oppression.⁷⁰ And Sangiovanni worries that if we make deference integral to solidarity, we cannot account well for symmetrical cases where equally oppressed agents bond together.⁷¹ For most critics, deference is merely instrumentally required in some cases, as when the best way to advance a cause is to rely on those with expert knowledge, or when a refusal to defer to those with first-hand experience of oppression communicates (anti-solidaristic) disrespect.

Can the functionalist account illuminate this disagreement? As before, we approach the question by asking what role the disputed feature (deference) plays in realizing solidarity’s point. Might deference be necessary to live up to our moral and/or ethical responsibilities? Might it help to avoid the pathologies we encounter under pervasive injustice? A first observation concerns the moral domain. Siding with critics like Dishaw and Sangiovanni, I find the idea that we best comply with our general moral reasons by adopting a stance of strict deference to a set of people picked out by a structural criterion (“the worst-off”) implausible. We must sometimes defer to others—often those with first-hand knowledge of injustice. But we also face scenarios where part of the injustice from which the oppressed suffer is that they are deprived of understanding what would improve their situation. Here, morality requires that we not defer. So, as far as our moral responsibilities are concerned, a categorical demand to defer would not advance solidarity’s point.

This leaves our ethical responsibility. It is here that the functionalist explanation attributes an important role to deference. Deference matters here because one core feature of attachments to others is that we are disposed to defer to their understanding of their interests. For example, Samuel Scheffler, discussing what is entailed by valuing one’s membership in a group, says that “one’s responsiveness to the group’s norms […] involves a posture of deference. In treating those norms as reason-giving even if one disagrees with them, one concedes to the group a degree of authority over the content of one’s reasons. Deference, no less than partiality, is involved in valuing one’s membership in a group.”⁷² Since one important part of solidarity is to form interpersonal bonds with those with whom one is in solidarity, and doing so requires an attitude of deference in some instances, deference does play an important role. Yet contrary to those who see deference as one of solidarity’s distinctive moral demands, the functionalist approach says that the required disposition is not unique to solidarity, but a corollary of valuing interpersonal bonds. Moreover, the relevant attitude of deference is not strict or categorical; you fail to appropriately value a relationship when you are not disposed to defer to others where their interests are much more affected than yours. But on many other occasions, one does not fall out of solidarity when one fails to defer.⁷³

VII. EXPLAINING SOLIDARITY’S VALUE AND DEONTIC STRUCTURE

Let us turn to the puzzle of solidarity’s value and its deontic structure. The difficulty we encountered with its value, recall, was that it remained unclear whether the value of solidarity relations derives exclusively from their contribution to the realization of some further good (per the purposive accounts), or whether solidarity has value that is (at least partly) independent of its aims (per the non-purposive accounts). Based on the functionalist story I have told, it seems that, first and foremost, we should care about solidarity because it facilitates two other things that are of value, namely living a good life and doing what morality requires. So, it seems natural to claim that solidarity is primarily valuable because it facilitates the achievement of independently valuable ends. This is welcome news inasmuch as this allows us to rule out that there is anything valuable about Mafiosi or Nazi solidarity.

However, the functional account allows that appeal to instrumental considerations is only one part of the story. Solidarity, in the way that I have described it, can also be part-constitutive of something that is itself non-instrumentally valuable. To bring this more complex additional feature out, it is helpful to return to the issue of motivation when acting in solidarity. Recall the idea, taken up by many authors, that solidarity somehow integrates self- and other-regarding motivation. While many have noted this feature, there is, to my knowledge, no satisfactory analysis of it in the literature. My suggestion is that explaining this feature is essential to understanding solidarity’s value (as well as its deontic structure, which I discuss below). The functional account provides such an explanation: because solidarity’s role is to facilitate alignment between two types of reasons, solidarity is always dually motivated. It is other-regarding in that it is constituted by a commitment to pursuing the just treatment of those picked out by a cause. But it is also self-regarding in that the person in solidarity, having created personal reasons through commitment, has tied her own self-realization to the achievement of just treatment for others. This is true even for those cases, like Bahar or Chams, where the one in solidarity is not part of the immediate cause-defined group whose just treatment is advanced. It is the ability of solidarity commitments to turn other-regarding causes into building blocks of one’s own self-realization that account for solidarity’s ability to “transcend the very dichotomy between altruistic and egoistic motivations.”⁷⁴

Now the more complex aspect of solidarity’s value is this: while the success of many of our worthwhile personal projects depends on the cooperative activities of others, their cooperation can matter in different ways. For example, in G.A. Cohen’s celebrated example, the member of a jazz band “fulfils himself only to the extent that each of the others also does so, and the same holds for each of them,” such that the result is a “concert of mutually supporting self-fulfilments […].”⁷⁵ Yet Cohen—elaborating what he takes to be Marx’s view of communism—insists that no delight in the fulfilment of others is required.⁷⁶ Other things equal, one is no less accomplished as a jazz musician when one treats the projects of musical self-realization of one’s band mates merely instrumentally, for jazz music is not the kind of thing whose value turns on the performer’s (self- or other-regarding) motives.

By contrast, self-realization of the kind achieved through solidarity fundamentally depends on our regarding and treating the self-realization of those cooperative others as something that matters non-instrumentally to us. When my act of solidarity (knowingly) contributes to the good of others, then I can understand it as a unique and especially ennobling kind of self-realization, namely a self-realization with and for others on reciprocal terms.⁷⁷ There is, moreover, a converse element in the domain of impersonal value: the world has gone better when some injustice ends as a result of a mutually committed group of people having made the fight for justice their project. The upshot of this is that solidarity seems to be part constitutive of, first, a uniquely valuable type of reciprocal self-realization for others, and, second, a uniquely valuable way of ending forms of injustice and adversity.

Solidarity’s deontic status. Let me finally turn to the puzzle about solidarity’s deontic status. Are duties of solidarity genuinely novel duties, or are they, as some have argued,⁷⁸ dependent on, or derivative of some more general duties we have, say duties of fair play or beneficence? I will suggest that there is no simple answer to this question: some duties of solidarity derive from general duties we have independently of solidarity, while others are grounded directly in the attachments established through solidarity commitments. Again, my functionalist explanation can help us to better understand why we face this complex condition.

Throughout, my claim has been that what renders solidarity unique is its functional role in helping us to live up to both our moral and our ethical responsibilities. Looking at our moral responsibilities, we find that many—but not all—of the moral reasons that we have are (or coincide with⁷⁹) moral duties. Often solidarity commitments that we make help us to comply with moral duties we already have on independent grounds. In such cases, those who maintain that duties of solidarity are derivative or conditional on other duties are correct. However, two additional points make matters more complex.

First, solidarity commitments can change the content of the general duties we already have. Many of our pre-solidarity duties are duties that require mere conformity. Think, for example, of a duty to do one’s fair share in a valuable cooperative endeavour. We discharge this duty when we do our fair share. It does not matter, as far as our duty is concerned, whether we do so because we think that this is what fairness requires or because we fear that others will exclude us from future cooperation if we free-ride on their efforts. But as I noted earlier, the demands of solidarity (like the demands of friendship and other intimate relationships) often require more than conformity. They require compliance, that is, they require us to discharge our duty for some reasons or with some motivation. Take Ava’s case: it seems plausible that she already has a moral duty, grounded in fairness, to participate in the strike/protest before she commits in solidarity. But the exact content of the duty changes once she has committed in solidarity and formed an evaluative attachment to those picked out by the cause. The upshot of this is that even when some duty derives from (or is conditional on) some non-solidarity consideration, solidarity can still reshape and precisify what the duty requires.

The second complication is that evaluative attachments can turn “mere moral reasons” into duties of solidarity. How might this occur? Our moral responsibility is wider than what we have a duty to do because some of our moral reasons aren’t duties. If the point of solidarity is to help us align our ethical and moral responsibilities, then there will be cases where the moral reasons that solidarity helps us to bring into harmony with our ethical ones aren’t duties. However, this does not mean that advancing the cause could not amount to a duty once we have made a solidarity commitment. Let me sketch two ways in which this could happen. Suppose that some moral reason does not amount to a moral duty because it would be too psychologically demanding for the agent to have this duty. But once the agent has committed, the psychological cost of investing time and energy weighs less heavily. After all, the agent has made this particular cause her self-chosen project. Since the “psychological burden” has gone down, doing what the cause requires now does constitute a duty. Here is a second scenario: suppose that you have a moral reason, but no moral duty, to help a stranger in moderate need (say with money for bus fare when they have lost their wallet). Yet suppose that you would have a duty to help a person with whom you share a more intimate connection, say a friend or a colleague, if they found themselves in a similar situation as the stranger. As solidarity commitments create evaluative attachment not just to causes but also to the people they pick out, the personal bonds we create through solidarity can turn strangers into comrades, and hence things we had mere moral reason to do into moral duties.

On the picture of the deontic structure of solidarity I have sketched, the landscape is diverse: some duties are derivative of prior non-solidarity duties, while others are grounded in our solidarity commitments. The functionalist account I have offered provides a persuasive explanation of this complexity.

VIII. CONCLUSION

I began with Bertolt Brecht’s proclamation that “He who deserts his fellow equals only deserts himself!” Brecht wrote Solidarity Song during the final years of the Weimar Republic as a rallying cry for fellow communists during times of violent struggles against a bourgeoning Nazi movement. So perhaps all that he wanted to get across to his comrades was the adage that “United we stand, divided we fall!”⁸⁰ This article has offered an interpretation of a deeper insight about solidarity that Brecht’s song might hint at: when you betray your comrades, you betray yourself. Through solidarity, you do right by other people—your “fellow equals”—but you also reconfigure your personal projects and build valuable attachments to others. When you betray solidarity, you do more than just wrong your comrades and hamper the success of a morally worthy cause. You also sabotage your own achievement of a life worth aspiring to.

Recognizing the potential for conflict between our moral and our ethical responsibilities is one of the hallmarks of a liberal approach to political morality. Within this tradition, the most elaborate response to this predicament is to advocate for a division of moral labor so that general moral requirements—and, in particular, duties of justice—are discharged by institutions, while we, as individuals, are, in the words of Thomas Nagel, “[left] relatively free to pursue agent-relative values in our personal lives.“⁸¹ Solidarity takes seriously the potential conflict between moral and ethical responsibilities, yet offers an alternative solution that avoids two charges often brought against the division-of-labor view.

One criticism, made from more radical perspectives, is that the liberal solution invites a decidedly unpolitical, “bourgeois” vision of our personal reasons and projects. Solidarity highlights, by contrast, that such political passivity does not follow from our need to reconcile moral and ethical responsibilities: we can (and should!) turn justice-given causes into personal projects and bonds, thus politicizing our private life.

Second, even among liberals, there may be a lingering doubt that the “division of moral labor” solution cannot offer us much guidance about how to conduct our lives under less-than-ideal circumstances. In the world we actually inhabit, institutions are often manifestly defective. They fall short of their aims unless pushed; they may be abused unless they are held to account. So the on-going success of outsourcing moral labor to institutions depends, under realistic conditions, on our on-going willingness to engage in political activism that keeps these institutions “on track.” Under these conditions, solidarity offers a much-needed guiding strategy that, unlike more impersonal-consequentialist alternatives, stays true to core liberal commitments.

Acknowledgements

For insightful feedback and/or written comments on earlier versions of this paper and its central ideas I would like to thank Jessica Begon, Friedemann Bieber, Carl Fox, Iason Gabriel, Richard Healey, the late Waheed Hussain, Jan Kandiyali, Faik Kurtulmus, Barry Maguire, Jonathan Parry, Angie Pepper, Miriam Ronzoni, Andrea Sangiovanni, Emily Sullivan, Philippe van Parijs, Kristin Voight, and Nicholas Vrousalis. I would also like to thank audiences at the European University Institute in Florence, the University of Manchester, Oxford University, the Max-Planck Institute for the Study of Ethnic Diversity in Göttingen, Utrecht University, and the 2023 Annual Economic Ethics Meeting. I’m also very grateful to the two anonymous Associate Editors at Free & Equal, whose comments significantly improved the paper. Finally, special thanks to Daniel Viehoff for invaluable comments and countless discussions. This article was written with the generous support of ERC Grant 771635.

Competing Interests

The author has no competing interests to declare.