Justice, emotions, and solidarity

ABSTRACT This paper discusses Habermas’s argument that justice requires solidarity as its ‘reverse side’, whereby the former provides the necessary global framework for establishing intersubjective solidarity whilst the latter constitutes an important precondition for igniting social and political change in the direction of social justice. In this paper I argue that such a paradigm of reciprocity might be fruitfully complemented by a less apparent yet substantial nexus: that between solidarity and perceived injustice, which I contend also triggers the emergence of solidarity. Drawing from Arendt’s thematisation of solidarity as a principle that stems from human suffering and recent scholarship on transitional post-conflict justice, I analyse the negative and reactive aspect of solidarity and the role of negative emotions in its emergence.


Introduction
Solidarity is a pivotal concept in today's discourse. Recent emergencies such as the European migrant crisis, the Covid-19 pandemic, and the resurgence of racist crime and violence have impelled the public to reconsider ways of uniting and protecting each other and fighting for shared political goals -all characteristics that are usually ascribed to solidarity relations. Despite the growing need to define solidarity and implement solidarity practices in today's societies, several difficulties emerge whenever philosophy engages with this idea. 1 One of the reasons why solidarity has seldom become a central topic in ethics as well as in other theoretical disciplines is the lack of a clear-cut and shared definition of this concept. In the relatively short history of the notion of solidarity, 2 it has been described as a political principle, a moral obligation, a civic value, a collective sentiment, and more. At the same time, in everyday language, the term solidarity is often understood in a purely descriptive way as a kind of fellowship that can emerge among individuals or social groups on the basis of their convictions, regardless of whether these convictions are morally and politically desirable. In order to address this difficulty, various attempts at categorising solidarity followed one another with the result that the concept was decomposed and its less apparent facets shown. Scholars distinguished different concepts and uses of solidarity and showed how despite its complexity and multifaceted nature, solidarity is a unitary concept that diverges from ideas that resemble it such as sympathy, friendship, and charity (Bayertz, 1999;Brunkhorst, 2005;Kahane, 1999;Prainsack & Buyx, 2017;Scholz, 2008). Unlike charity, solidarity implies an equal relation among peers who share goals and ideals with at least an expectation of reciprocity. Unlike sympathy and friendship, solidarity relations motivate collective action, risk taking, and longer-term political consideration and planning (Meacham & Tava, forthcoming). In light of these characterisations and distinctions, we can define solidarity as a type of intersubjective relation that potentially emerges when people share political goals and ideals and are willing to collectively and reciprocally shoulder the burdens that pursuing such goals might entail.
The aim of this article is to discuss Habermas's (1990, p. 47) argument that solidarity is required in today's societies because it represents the 'reverse side' of justice. Instead of explaining the emergence of solidarity relations on the basis of the reciprocity and mutual dependence of solidarity and justice, I contend that what engenders solidarity is not simply an abstract demand for justice but also concrete emotional reactions to conditions of perceived injustice. 3 This alternative approach builds on Arendt's (1990) understanding of solidarity as a reaction to human suffering and a possible guiding principle for political agency and on Scholz's (2008) definition of political solidarity as a principle fundamentally oriented towards social change. For Scholz, people who are in political solidarity react to conditions of injustice and oppression. What unites them is neither shared attributes nor the desire for mutual protection, but rather a shared commitment to a cause alongside with the presence of specific moral obligations. What seems to motivate this form of political solidarity is therefore its negative and reactive aspect. It is a reaction that naturally stems from experiences of perceived injustice. It is important to note from the outset that I am not arguing that solidarity is the sole or prevalent reaction to perceived injustice. Depending on the personal dispositions and social contexts we analyse, the same experience of perceived injustice might in fact generate a variety of reactions that also include (for instance) competitiveness and antagonism. What I am arguing here is simply that solidarity is one of these potential reactions. Similarly, I am not arguing that all kinds of solidarity stem from perceived injustice, but rather that perceived injustice is one important source (among many others) of this intersubjective relation. 4 An important part of the following analysis consists of clarifying the role that negative emotions play in the way human beings react and find themselves in solidarity when they face unjust scenarios. To do that, I discuss the role of public anger, resentment, and indignation in transitional justice in order to clarify how these emotions contribute to the emergence of solidarity relations. Thematising this negative and reactive aspect of solidarity does not mean that justice and solidarity are separate or incompatible. It simply means that an alternative and more substantive trail towards solidarity can be blazed if we look at its connection with injustice.

Justice and solidarity
In 'Justice and Solidarity: On the Discussion concerning "Stage 6"', Habermas (1990) rejects any characterisation of solidarity as supererogatory and strongly advocates the necessity of conceiving of solidarity as 'the reverse side of justice' (p. 47). 5 For him, this implies the need to understand justice and solidarity as co-original normative principles that are both necessary to frame a moral theory that is at the same time rationally acceptable and informed by the concrete social landscape from which it arises. This stance seems to contradict the assumption of rationalist neo-Kantian ethics that a system of justice relies upon the individual rights of autonomy and selfdetermination. The human ability to freely determine one's own moral standpoint on the sole basis of practical reason might in fact be hindered by solidarity, which requires social relations of mutuality and accountability among individuals and institutions. By reintroducing solidarity into the normative discourse, Habermas aims at responding to the criticism, mainly stemming from feminist care ethics (Gilligan, 1982), according to which neo-Kantian deontology inevitably neglects the existence of concrete moral subjects insofar as it is exclusively concerned with abstract universal principles.
On the one hand, Habermas (1990) reiterates the necessity of thinking of ethics in a universal fashion: 'I hold that it must be possible to decide on firm grounds which moral theory is best able to reconstruct the universal core of our moral intuitions, that is, to reconstruct a "moral point of view" that claims universal validity' (p. 33). On the other hand, he is sensitive to the aforementioned criticism and therefore decides to hone his ethical standpoint by looking at Hegel's critique of Kant. Although Hegel disagrees with the abstract universalism of Kant's ethics of duty, he also rejects the particularism of concrete welfare as it figures in Aristotle's ethics (Habermas, 1990, p. 42). For Habermas, the gap between the universal scope that ethics must maintain and the need to look into the social and communicative aspects of human morality can be bridged by showing that only through processes of socialisation can humans become autonomous and self-determining moral agents. In this sense, solidarity acquires a completely new role insofar as its capacity to aggregate people on the basis of a shared communication framework allows it to trigger such processes. For this reason, not only is the concept of solidarity not detrimental to our understanding of universal justice but in fact it becomes a necessary component of it.
In 'Justice and Solidarity', in order to refute the criticism from care ethics, Habermas discusses alternative attempts to steer moral theory towards broadened levels of socialisation. In particular, he looks at Lawrence Kohlberg's theory of moral development as one of the main examples of this endeavour (Kohlberg et al., 1990;Puka, 1990; both as cited in Habermas, 1990). According to Habermas's interpretation, Kohlberg aims with his theory at bringing together the moral principle of justice and concern for the welfare of others. To do so, he proceeds through three fundamental steps. First, he relativises the idea of justice and associates it with a second principle -benevolence -with which justice stands in tension. Whilst justice refers to the equal right to attain personal freedom, benevolence is concerned with the welfare of others, compassion, and community spirit. Second, Kohlberg argues that both justice and benevolence derive from a higher principle, which is equal respect for the dignity of each person. Third, he shows how both justice and benevolence arise from the procedure of ideal role taking -that is, from the ability that humans acquire through cognitive growth to understand the perspective of others. According to Habermas (1990), the greatest difficulty in Kohlberg's theory concerns the fact that equal respect refers only to individuals and not to the collective: A principle of benevolence "derived" from [equal respect] might on that account be able to ground concern for the welfare of one's fellow man (or for one's own welfare), but it could not ground concern for the common welfare, and thus not the corresponding sense of community. (p. 45) Hence, including the principle of benevolence in moral theory does not suffice for recognising the social and collective network through which humans determine themselves as moral actors. Habermas's solution to this impasse consists of introducing a discourse-ethics alternative that fully acknowledges the pivotal role of the speech community and intersubjectively shared lifeworld in the process of self-determination of individuals. For him this entails substituting the concept of benevolence with that of solidarity in the role of co-original moral principle alongside justice: [Solidarity] is rooted in the realization that each person must take responsibility for the other because as consociates all must have an interest in the integrity of their shared life context in the same way . . . . Justice concerns the equal freedoms of unique and self-determining individuals, while solidarity concerns the welfare of consociates who are intimately linked in an intersubjectively shared form of life-and thus also to the maintenance of the integrity of this form of life itself. Moral norms cannot protect one without the other: they cannot protect the equal rights and freedoms of the individuals without protecting the welfare of one's fellow man and of the community to which the individuals belong. (Habermas, 1990, p. 47) The substitution of benevolence with solidarity determines a shift in our understanding of the purpose of morality. Morality must not only ensure equal respect and treatment for each individual in society, but also protect intersubjective relationships of mutual recognition. To achieve these interconnected goals, both justice and solidarity are required. To summarise, we might describe this shift from Kohlberg's moral development to Habermas's discourse ethics as a passage from a three-sided structure in which one side subsumes the others ( Figure 1) to a four-sided structure in which all components are placed on the same level ( Figure 2): By embedding solidarity in a moral structure wherein it contributes alongside justice to form equal respect and mutual recognition, Habermas aims at proposing a substantial reinvention of this concept. Solidarity understood as the reverse side of justice diverges from what Habermas labels as 'premodern forms of solidarity' -namely, all those forms of mere fellowship and followership of which the Nazi Führerprinzip is the best and most dramatic example. In order to contrast his idea with these forms of solidarity, whereby the aggregating principle -be it tribe, race, nation, or blood -has nothing to do with moral duties and norms, Habermas envisions an idea of solidarity that has universal morality at its very core. Whether this theoretical endeavour has been successful is open to question. Is this tying of solidarity to justice the only way to discard traditionalist, premodern interpretations of this relation and to conceive a new, universal idea of solidarity, which could be the basis for forming a future transnational community? What is certain is that Habermas has gradually distanced himself from his theory of solidarity as the reverse side of justice. In his recent works on the ongoing crisis of European institutions, he emphasises the distinctively political character of solidarity, which sets it apart from both moral and legal normativity. To do so, he also rejects the reciprocity and convergence between justice and solidarity that he previously advocated. This modified perspective emerged in a public lecture that he delivered in 2013 at the University of Leuven (Belgium). In this lecture, Habermas (2013) argues that 'solidarity loses the false appearance of being unpolitical, once we learn how to distinguish obligations to show solidarity from both moral and legal obligations. "Solidarity" is not synonymous of "justice", be it in the moral or the legal sense of the term' (p. 8). Unlike moral obligations, which derive their strength from the presence of 'pre-political communities' such as the family and from the trust that these communities can inspire, solidarity can only rely on 'political associations or shared political interests' (Habermas,p. 8). And solidarity can be neither enforced nor categorically required as though it was a legal norm. By firmly placing solidarity in the realm of politics, Habermas wants to safeguard this principle from all those pre-political bonds that are often associated with it and that according to him contributed to turning solidarity into a conservative and reactionary concept. The kind of political solidarity that Habermas (2013) has here in mind is markedly detached from this moral substratum and acquires a new dynamic and future-facing aspect, whereby its authentic aim is not any predetermined conception of mutual recognition but social struggle and change: 'This forward-looking character becomes particularly clear when solidarity is required in the course of social and economic modernisation, in order to adjust the overstretched capacities of an existing political framework, that is to adjust eroding political institutions to the indirect force of encompassing systemic, mainly economic interdependencies that are felt as constraints on what should be in the reach of the political control of democratic citizens' (p. 9).
Habermas's attempt to unearth this progressive and (to use his terminology) 'offensive' character of political solidarity suggests the opportunity to explore new theoretical paradigms beyond that of the reciprocity and dependence between justice and solidarity. In the following section, I follow this lead by exploring what I contend is one of these alternative paradigms. Habermas (2013) concludes his Leuven lecture with a strong emphasis on what he called the 'offensive' character of solidarity. By that he means to indicate a strongly political understanding of this notion, whereby being in solidarity does not entail any adherence to the natural or quasi-natural aspects that the members of a community share, but rather mutual agreement to act in unison in order to overcome crisis. As the above shows, this change of perspective problematised the relationship between justice and solidarity. A way to further develop and concretise Habermas's intuition consists of introducing a new paradigm for thinking about solidarity, one that, rather than focusing on the reciprocity and dependence between justice and solidarity, grounds itself on the contrast between solidarity and injustice. This change of perspective permits us to identify solidarity on the basis of its capacity to contrast with concrete situations of perceived injustice rather than to buttress existing notions of justice. In order to develop this alternative paradigm, I build on Hannah Arendt's theory of action, which helped to thematise this negative and reactive character of solidarity.

Solidarity and injustice
Both Habermas's and Arendt's insights into solidarity emerge out through examining the same phenomenon -namely, totalitarianism. As we have seen in the previous section, one of the reasons why Habermas decided to initially embed solidarity in universal justice was to detach it completely from any 'premodern' form of fellowship. The same concern is also at the basis of his decision to ultimately detach solidarity from justice, insofar as maintaining a reciprocity between these two principles would mean conceiving of solidarity on the basis of an unenforceable morality, which is typical of those 'prepolitical communities' that he wants to reject. The archetype of a 'premodern', 'pre-political' community that Habermas has in mind here is Nazi Germany. The main concern of whoever aims at advocating a new form of solidarity should be to prevent that solidarity from taking the form of a brotherhood united by the ideology of a charismatic leader.
By advocating the centrality of the public space within the democratic domain, Arendt has a similar concern in mind. According to her interpretation, one of the conditions for the rise of totalitarianism is the dissolution of such public space. Totalitarian societies are characterised by the loneliness of their members, who are held together so tightly that 'it is as though their plurality had disappeared into One Man of gigantic dimensions' (Arendt, 1973, pp. 465-66). Such a tight social unity -whose functioning is summarised by the formula 'All for one and one for all' (Habermas, 1990, p. 47) -might easily be mistaken for an example of solidarity. In actuality, however, a fundamental component of solidarity is missing in this social unity -namely, plurality. To counter this pseudo-conception of solidarity, whereby individuals are forced to surrender their uniqueness in order to join a uniform ideological structure, an open and diverse public domain has to be re-established. According to Arendt, this outcome is attainable only as long as speech and action are preserved and constantly re-instantiated within the state. This is where solidarity becomes relevant. Solidarity is for Arendt a dynamic, world-creating human relation that enables individuals to share projects and plans of action without losing their distinctiveness and singularity, and it is therefore precisely what allows humans to re-establish the public domain. As Hansen (2004) points out, for Arendt, being in solidarity means 'bearing with strangers' -that is, entering a domain that is never entirely familiar and that has therefore to be filled with speech and action in order to allow its inhabitants to liaise with each other and to learn how to actively share their public space. This conception relies upon several notions that are pivotal in Arendt's ethics and philosophy of action, such as natality, finitude, uniqueness, and plurality. What characterises human beings from birth to death is not their similarity -the fact that they all belong to the same species -but their uniqueness (Arendt, 1998, pp. 8-9). Each finite being adds an incommensurable element to the world, and plurality is nothing but the cognitive and practical interplay among these elements. In this framework, solidarity plays an important role insofar as it embodies the political relation through which individuals can form this plurality without losing their existential uniqueness and moral autonomy.
For the purposes of this article, it is of particular interest to notice what in Arendt's view triggers the formation of solidarity. Although her comments on solidarity and its formation are scarce, a brief yet poignant passage from On Revolution is especially relevant to this subject, to the extent that it generated a broad discussion among Arendtian scholars (Allen, 1999;Butler, 2010;Gaffney, 2017;Reshaur, 1992). In this passage, Arendt argues that solidarity among people stems from human suffering. What she refers to here is not a generic notion of suffering, but the peculiar pain that people feel whenever they endure oppression and exploitation. When humans experience, either directly or indirectly, such injustices, they tend to establish a 'community of interest' with the oppressed and exploited (Arendt, 1990, p. 88). In other words, when people are faced with an unjust situation, they can decide to act in solidarity in order to defend themselves or whoever is suffering from this injustice. This definition perfectly illustrates the reactive and 'offensive' character of solidarity. Moreover, it allows us to disengage solidarity from any form of identity principle, whereby what unites people are precise characteristics that they all share (be they social, national, racial, or other). 6 In the kind of solidarity that Arendt envisages, people are exclusively united by the negative emotions that arise when they experience something that they perceive as bad.
Despite the role that emotions play in the arousal of solidarity, Arendt (1990, p. 89) is very clear in pointing out that solidarity is not about emotions but about ideas: 'This solidarity, though it may be aroused by suffering, is not guided by it . . . ; it remains committed to "ideas" -to greatness, or honour, or dignity -rather than to any "love of men"'. This is what distinguishes solidarity from pity, which for her is nothing but a sentiment driven by particular passions. Solidarity is neither a sentiment nor an emotion but a political relation: 'It partakes of reason, and hence of generality, is able to comprehend a multitude conceptually, not only the multitude of a class or a nation or a people, but eventually all mankind' (Arendt, 1990, p. 89). To highlight this point, Arendt goes so far as to say that solidarity is something cold and dispassionate. We can argue that, in her understanding, solidarity represents the emotionless reaction to the highly emotional shock that injustice can cause. This reaction, however, is not an end in itself, but in turn leads to something else, which is what Arendt is most interested in. Since solidarity 'partakes of reason' and concerns ideas, it can 'inspire and guide action' (Arendt, 1990, p. 89). In the face of injustice crying out for action, human behaviour is not restricted to emotions such as resentment and indignation. Intolerably unjust circumstances encourage people to constitute a 'community of interest' with the victims of such circumstances, even though these victims are complete strangers. To summarise, Arendt's account of solidarity seems to indicate a complex structure (Figure 3) whereby the emergence of solidarity is caused by conditions of injustice through the medium of negative emotions, with the aim of intervening against such injustice.
Another interesting aspect of this structure concerns the distinction between private and public. Whilst the emotions that suffering causes are necessarily internalised and therefore belong to one's private life, by turning our negative emotions into a solidaristic community of interest with the aim of acting against injustice, we reopen and enter the public domain. In this sense, solidarity can be viewed as an intersubjective relation that allows human beings to rebuild that sphere of plurality and commonality that the totalitarian mechanism threatens to dismantle.
Although this scheme shows how negative emotions can justify the emergence of solidarity, it must be noted that this is not always the case. Not all negative emotions trigger a solidaristic response, and, even when they do so, not all these responses serve the function of fighting the injustice that originated them. Emotional responses to injustice can, for instance, be disproportionate and generate further injustice, rather than fixing the original one. In this sense, the scheme that we gathered from Arendt's analysis simply describes one possibility for generating solidarity, rather than clarifying the norms of its formation. In what follows I provide a more precise account of what role negative emotions can play in the emergence of solidarity relations.

Negative emotions
In the previous section, I mentioned the specific role that negative emotions can play throughout the complex process in which humans react to the painful experience of injustice and strive to transform such pain into a solidaristic response. In order to fully explain this point, questions regarding the nature of emotions, and in particular negative emotions such as anger, resentment, and indignation, should be explored at length. The scholarship on emotions is vast and encompasses several disciplines including, among others, phenomenology, cognitive psychology, and neuroscience. From the groundbreaking work by William James through Martha Nussbaum's recent analyses of political emotions, this field of research has acquired distinctive importance for philosophy.
Following up on what has emerged so far in this article in relation to Arendt's theory of action, an aspect of emotions that is particularly relevant is what we might call their intentionality or directionality. Unlike feelings, which maintain an element of passivity and unpredictability, emotions -both positive and negative -are concerned with the way individuals interact with their surroundings, both bodily and cognitively. As Maiese (2014) phrases it in an article on this theme, emotions are ways of 'engaging with and making sense of one's surroundings' and, as such, they determine how human beings care about 'objects, events, states of affairs, each other, our own lives, and even our own caring' (p. 514; see on this also Ratcliffe, 2002;Solomon, 1997). Emotional experience has a specific intentional directedness, as it allows us to transform our bodily feelings into thoughts and actions and therefore to determine the cognitive focus of our emotions. On a similar note, Theodorou (2014) remarks that emotions are 'the intentional apprehension' (p. 627) of pleasure and pain. This position echoes a long phenomenological tradition in the study of emotions that dates back to Husserl's (1998) understanding of emotions (Gefühle) as intentional experiences of value and extends to Scheler's (2009) ethics of values and his analyses of emotional life. 7 This reference to value is of utmost importance insofar as it highlights a normative aspect of emotions that would be otherwise hardly identifiable. Emotions are essential to understanding how we value the world, and it is on the basis of this judgement of value that we decide how to react to the stimuli that we receive in our everyday life. 8 Therefore, responding to emotions acquires a remarkable role in human existence. Understanding emotions as actual experiences of value means rejecting their characterisation as mere sentimental contingencies and acknowledging that they are fundamental components of practical reason.
Taking emotions seriously is also the more or less explicit guiding principle of a number of moral and political philosophers who tackled this issue in recent years (Hatzimoysis, 2003;Kassab, 2016;Solomon, 1997Solomon, , 2004Solomon, , 2007Wollheim, 1999). Nussbaum's (2001Nussbaum's ( , 2004aNussbaum's ( , 2004bNussbaum's ( , 2013 extensive analysis of emotions is one of the most meaningful examples of this endeavour. In Upheavals of Thought, Nussbaum (2001) argues (paraphrasing Proust) that emotions are 'geological upheavals of thought': inasmuch as they 'shape the landscape of our mental and social lives' (p. i). Since they are 'intelligent responses to the perception of value', we need to consider them 'as part and parcel of the system of ethical reasoning' (p. i). Nussbaum not only attempts to explore the ethical relevance of emotions, but also focuses on their impact on political life. This aspect of her analysis becomes central in Political Emotions, in which she directly addresses the relationship between emotions and political stability and claims that if liberal democracy wants to aspire to justice and equal opportunity for all, it should learn how to provide the 'political cultivation of emotion' (Nussbaum, 2013, p. 2). But what kind of emotion is here at stake? Nussbaum's analysis is fundamentally grounded on the emotion of love and on how love influences the ways individuals commit themselves to and participate in common goods. 9 In this context, negative emotions seem to play a secondary role, as they are mainly thematised as the reverse side of love and compassion. Fear, envy, and shame, for instance, appear as nothing but 'compassion's enemies' (Nussbaum, 2013, p. 314). This is surprising if we consider the massive political impact that negative emotions have had in recent history. Phenomena such as political dissidence, upheavals against authoritarian regimes, and postconflict democratic transition are regularly accompanied by negative emotions such as anger, resentment, and indignation. The recent protests that followed the murder of George Floyd in Minneapolis (United States) are a clear example of how shared negative emotions that stem from an experience of manifest injustice can become conducive to social and political justice in the form of calls for police accountability, condemnation of racial violence and collective historical amnesia, and attempts at education reform (Banaji, 2020). This fact should encourage researchers to recognise and constantly engage with negative emotions in order to better assess their political potentialities.
Among the various angles from which we can address the potential of negative emotions, that of transitional or postconflict justice is particularly relevant to this article. In a recent book on this topic,  argues that it is necessary to give due recognition to the negative emotions that citizens mobilising against past atrocities can develop. At the same time, a functioning democratic regime must ensure that the rights of those who are targeted by such emotions are also acknowledged and defended. This balance becomes particularly hard to maintain in the context of democratic transition, wherein 'concerns about stability and peace are often given priority at the expense of substantive, meaningful justice claims' (Mihai, 2016, p. 4). In other words, in a newly established democracy policy makers might tend to bury their country's violent, predemocratic past in order to avoid divisiveness and instability. In this context, collective memory, and the negative emotions that this memory evokes, can be seen as a hindrance to democratisation, rather than as a principle conducive to it. Therefore, processes of reconciliation are often implemented in order to cut the ties with a problematic past and to establish a forward-looking political agenda. 10 Mihai rejects this account and argues that, in a process of democratisation, negative emotions are not mere obstacles but essential markers that enable citizens to recognise and evaluate injustice. This evaluative character, which (as we have seen above) is also central in the phenomenological understanding of emotions, grants negative emotions their normative weight and makes them 'legitimate objects of concern for any democratic order' (Mihai, 2016, p. 7). Overlooking this emotional component would involve undermining the normative integrity and political legitimacy of a democracy. For instance, overlooking or repressing public anger might undermine the legitimacy of a government and foster distrust and cynicism. On the other hand, unchecked public anger can also lead to detrimental outcomes, such as uncontrolled revenge and victimisation. 11 Phenomena such as anger, resentment, and indignation 12 are worthy of attention not only because overlooking or using them improperly can have harmful consequences. To the contrary, Mihai (2016, p. 8) claims that negative emotions bring opportunities as well as dangers. Particularly, 'engaging publicly with citizens' politically relevant emotional responses represents a first opportunity for institutions to embark on a process of democratic emotional socialization'. By emotional socialisation Mihai (2016, p. 64) means those processes that enable individuals to form context-appropriate emotions and to express them in culturally sensitive responses. In other words, by sharing and comparing their emotional evaluations (and specifically their negative emotional reactions to conditions of perceived injustice), people can both limit undesirable behaviour and encourage the wider endorsement of societal values. As Solomon (1997) writes: Every emotion establishes a framework within which we commit ourselves-or refuse to commit ourselves-to our world and to other people. Every emotion lays down a set of standards, to which the world, other people, and most importantly, our Selves are expected to comply. (p. 141, as cited in Mihai, 2016, p. 65) Even though Mihai does not use the word solidarity to describe this process of emotional socialisation, we might argue that a link exists between these two notions. As the above analysis of Arendt's account of solidarity has shown, the emergence of solidarity relations out of experiences of suffering and injustice paves the way to the re-creation of a public sphere in which people are free to share and discuss their emotional status in order to find ways to overcome past traumas. This is also what Mihai has in mind when she refers to the socialisation that negative emotions can generate in the aftermath of conflict scenarios. This is also why she insists that transitional justice requires an emotional education. People have to learn how to make good use of their negative emotions in order to prepare the ground for successful emotional socialisation. This is the same point that Nussbaum (2013, p. 2) also makes when she argues that justice requires the political cultivation of emotion. In this framework, solidarity represents a fundamental vector that allows individuals to turn their internalised negative emotions into processes of socialisation. These processes will in turn give those who are involved in them the chance to tackle the injustices that originated those negative emotions in the first place. This kind of solidarity takes the form of what Habermas and Arendt mean by this term. What unites people in this intersubjective relation is neither their sense of identity or belonging nor any positive similarity but their negative emotional reaction to something that strikes them as unjust.
In light of what emerged regarding the negative and reactive connotation that solidarity acquires whenever we try to disengage it from a positive theory of justice, this discourse about the functioning and effects of negative emotions in transitional justice becomes particularly relevant. Whilst, following Nussbaum, we might argue that 'love matters for justice', negative emotions such as anger, resentment, and indignation matter for solidarity insofar as they prepare the ground for its formation without, in so doing, anchoring it to any fixed notion of identity. In this sense, learning to make good use of such negative emotions -understanding how they can foster emotional socialisation and solidarity relations -could be a first step towards a redefinition of the concept of solidarity.