In a report commissioned by the Nuffield Council on Bioethics , and in response to the different and often conflicting understandings of solidarity in the literature, the authors of this article have developed a working definition of solidarity. It is based on an extensive analysis of earlier understandings of solidarity. Since the first iteration of our own working definition of solidarity in 2011, we have expanded and revised it on several occasions following helpful feedback from colleagues (e.g., [39, 49, 50]) and insights obtained from applying it to practical contexts [51–53]. In its most elementary form, we understand solidarity as an enacted commitment to carry the ‘costs’ (financial, social, emotional, and other contributions) of assisting others with whom a person or persons recognise similarity in a relevant respect .
Six qualifiers are in place. First, we understand solidarity first and foremost as a practice, that is, as purposeful engagement with the world [55, p. 4]. Solidarity is thus something that is enacted, not merely felt or thought; it is not an abstract concept. This means that analyses of solidarity need to pay careful attention to the context of a specific situation, including the policies, relations, and related practices that enable solidaristic practice.
Second, by ‘costs’, we refer to any contribution (e.g., in terms of time, effort, emotional investments, or money) that people make to assist others. Small things, such as giving up our own comfort to offer somebody a seat on the bus, count as ‘costs’ as much as big things, such as donating an organ or paying into a solidaristic healthcare system. That people accept such costs for the sake of helping others when practicing solidarity does not mean that they cannot, at the same time, also benefit themselves. It is only when self-interest is the main motivation that we do not consider the resulting practice as solidaristic.
Third, according to our definition, people practice solidarity with others with whom they recognise similarity in a relevant respect. This requirement is met if a person (or persons) considers herself to have something in common with the others who matter in a specific situation. Two things are important to note here. One is that the context of a specific practical situation determines the criteria of relevance. In a situation where a person offers to help a colleague study for a much feared exam because she knows what it is like to be anxious prior to an exam, this anxiety is the similarity in the relevant respect that gives rise to her solidaristic practice. That the two people in our example are different in many other respects—e.g., in religious or political beliefs—is irrelevant for the practice of solidarity in this situation. Thus, our understanding of solidarity does not assume that people are all essentially similar and that differences do not matter. On the contrary, solidaristic practice regularly takes place in a context of stark difference between persons; it takes place despite these differences. But it is the relevant similarity that people perceive between themselves and others that gives rise to the solidaristic action (and that we mean when we speak of a symmetrical relationship at the moment of practicing solidarity).
The other important thing to note is that the relevant similarity that a person perceives between herself and another is entirely subjective; we do not believe that people have objective characteristics that are, or should be, recognised as things that bind people together. To stick with our aforementioned example, a person’s offer to help her anxious colleague could just as well not recognise the relevant similarity and not enact solidarity if, for example, she were to focus on what sets her apart from her colleague. The colleague may belong to a social elite that she despises, or perhaps the colleague is very religious, while Lin is staunchly atheist. What people recognise as a relevant similarity is subjective, but not arbitrary. Political discourses can make it more or less likely that individuals perceive similarities rather than differences. A political discourse that foregrounds how much additional public money is spent specifically on immigrants fosters a situation in which people start to see immigrants as different from them. All that they share in common moves to the background. In contrast, a political discourse that highlights how hard most immigrants work to build a decent living and to contribute to society in their new homes is conducive to people focusing on the similarities.
Fourth, in order to focus discussion on the level on which solidaristic practices take place—ranging from interpersonal to being part of the ‘fabric of society’—we distinguish between three tiers of solidarity. The first tier of solidarity refers to solidaristic practice between individual people. Our vignette of a student providing help to her colleague is an example of solidarity at this level. If practices of solidarity between people are so common in a given context or community that they become something ‘normal’, then we speak of second tier solidarity. If the values or principles enacted and emerging through group or community-based practices in this manner solidify further and become written into contractual, legal, or administrative norms, then we have instances of third tier solidarity. The relationship between the three tiers is such that solidaristic norms and provisions at the third tier have often emerged out of initially more informal practices of solidarity at the interpersonal (first tier) or communal or group level (second tier). But of course, not all inter-personal practices at the first tier actually solidify into practices and norms at the second and third tiers. In societies where discursive, political, and economic structures emphasise and foster concern for others, and where the wellbeing of individuals is seen as closely connected to the wellbeing of others, these structures provide the ‘glue’ between the three tiers. They provide the background conditions for solidarity to grow and proliferate. If such structures are not in place, then even though solidaristic practice at each of the tiers may emerge, they would hang ‘in thin air’. In such a situation solidaristic practices would be unlikely to proliferate, flourish, and solidify.
Fifth, many authors see solidarity as something that is directed mostly towards vulnerable people [56, 57]. The role vulnerability plays in our framework hinges on the notion of similarity. One of the core features of solidarity is that it foregrounds similarities between people, and that these similarities are determined by the specifics of a concrete practice or setting. As argued above, while two people, or members of different groups, may be very different in many respects, one single similarity, if it matters enough in a concrete situation, can give rise to solidarity. If we have, for example, experienced a serious illness earlier in our lives, we may donate money and provide other means of support to others who suffer from the same disease, even if we have never met them in person and they live on the other side of the world. The shared experience of living with this illness becomes a defining moment in our practice of solidarity, even though there may be nothing else that we see ourselves having in common with the people whom we are helping. The shared experience is what makes us assist these people. This assistance, in turn, is typically something that affirms, helps, or supports others, and not something that harms them. It is in this sense that vulnerability matters. Despite the fact that what motivates our action is a commonality that we consider ourselves sharing with others, in the concrete situation in which solidarity is enacted, it is they, and not us, who are in need of support. That they are vulnerable and in need of support in this moment thus determines the direction of the support in the concrete instance of solidarity. But it does not change the fact that commonality between us, and not our differences, gives rise to our action.
Sixth, many authors see reciprocity as closely related to, or even synonymous with, solidarity. Indeed, the relationship between these concepts is such that for solidarity to grow and institutionalise, a certain level of reciprocity is required. But how exactly does reciprocity support the practice and institutionalisation of solidarity? As mentioned above, if reciprocity is the decisive or even the only motivation for a practice, then this practice should be called solidaristic. But particularly at higher levels of institutionalisation, indirect reciprocity can play an important role for stabilising solidaristic arrangements, and overall attitudes of reciprocity will help maintain and enliven solidaristic policies and laws.
This understanding of solidarity shares elements with definitions from other authors, and includes some features that resonate with the historical understandings briefly introduced in our first section above. However, at the same time, this conceptualization serves to divest the concept of solidarity of some of the more overtly partisan connotations it has been associated with in the past. In our understanding, solidarity is not an intrinsic good or a ‘leftist’ ideal; neither is it tied to or emergent from a particular understanding of a nation state or the common good. The normative value of the concept as such—independent of its concrete instantiations—is that it appreciates and facilitates non-calculating mutual support. As such, and possibly in contrast to more particularistic understandings of solidarity, this concept lends itself well to guiding policy and practice to address issues with global relevance.
In the next section, we provide an example of how solidarity can guide policy in an area that is of increasing relevance locally and globally, namely, the mitigation of harms emerging from the use of personal data. We argue that this solidarity-based governance framework can be fruitfully implemented on both sides of the Atlantic, irrespective of the differences in doctrinal and cultural stances on the political value of solidarity.