University of California, Berkeley 
“Researchers in the sciences of society are bound up with the human equipment of life together: their intervention is not limited to observing and modelling but contributes unfailingly to the elaboration of this equipment in virtue of the systematic viewpoint they adopt.” (Thévenot, 2007, p243)
The social sciences are built on the premise that the success of human society depends on the successful accomplishment of solidarity in some form or other, from the development of common understandings, collective goals and ideals, to the intensity of exchange, cooperation, and reciprocity. For sociologists especially, this presumption gives a sense of coherence to the idea of “society” itself, and which in turn may underpin our epistemological confidence that the world can indeed be explained. While “solidarity” itself is too vague an idea to be a directly observable in the world, our disciplinary commitment to its latent presence underpins all manner of measures and diagnoses of interpersonal and intergroup dependencies, collective responsibilities, common interests, emotions and sympathies.
Holistic metaphors of unity and coherence have been with sociology since its beginning, from Comte to Durkheim, from Spencer to Parsons (Levine 1995). Social theorists have long mixed the sheer fact of “living together in the world” (Arendt 1958) together with endorsements of particular forms of society. Solidarity sits uneasily between the descriptive and the normative, blurring the distinction between the object it claims to qualify (the social process) and the qualification itself (normal/pathological; good/bad). As sociologists we tend to value solidarity as such, but the concept is Janus-faced. In practice, the politics of collective belonging and organization is rarely unconditional. Some of our most celebrated solidaristic achievements were built on exclusion and division (Rana 2014). Think, for instance, of how the US labor movement often chose white solidarity over class solidarity (DuBois 1999); or of the nativist and racist nature of the extension of economic and social rights during and after the New Deal (Quadagno 1996, Fox 2012, Katznelson 2014); or of the persistence of beliefs about those deserving and undeserving of public assistance (Bloemraad et al. 2019). We can also recall the classist, and sometimes racist, myopia of many recognition-focused social movements (starting with the early women’s movement), the anomic splitting up of recognition claims into ever smaller “groupist” subcategories (Brubaker 2002), the difficulty of deriving social power from claims of social injury (Brown 1995), and the propensity of “affirmative” recognition remedies to generate resentment and backlash from those in the unmarked category (Fraser 1995).
While it is easy, in retrospect, to acknowledge these pathologies of solidarity, the concept’s double-edge persists in subtle ways even amongst those nominally committed to inclusive and expansionary conceptions of society. In a dilemma at least as old as Durkheim, for example, we may have come to look at the subjective experience of others as radically different and intrinsically unbridgeable, and regard this very state of affairs as a form of violence. Solidarity’s political conundrum is that (to use Nancy Fraser’s terms) the cultural politics of recognition often trumps the socioeconomic politics of redistribution.
And yet, as Fraser foresaw, another tension is possible, between a “transformative politics” which plays down group boundaries in both the economic and cultural spheres, and an “affirmative politics” which makes them more salient. That tension is surfacing today. On the one hand, progressives aspire toward ever more inclusive economic, social and cultural rights, such as universal health care, basic income, free college tuition, marriage equality, gender equality and un-differentiation, climate action (which by its nature has to be global), the thinning out of the distinction between legal and illegal migration, or the celebration of spontaneous acts of unconditional “fraternity” against growing institutional restrictions on it. On the other hand, an affirmative politics of a different kind has asserted itself, determined to promote deservingness as a criterion of inclusion, to take away cultural rights in the name of the affirmative beliefs and feelings of “the majority,” to turn the national polity into a symbolic and material fortress, and to restore pride in an unsavory historical past. Both of these politics arguably feed off of each other. Each side poses a threat to the other side, and thus their confrontation provokes a stronger response from both. (Mizrachi 2016) The re-appropriation of affirmative recognition and redistribution by the political right may have the effect of driving the left away from group-based claims and toward the transformative terrain of economic and cultural universalism –and vice versa. Whether we are witnessing the last and foul gasp of a disappearing world, or the painful birth of a new one, who knows (Fraser 2019). But in the uncertain struggle between the two lie the promises and perils of solidarity in the 21st century.
 My thanks to Chris Muller and Kieran Healy for comments and suggestions.
 This conversation has motivated the two invited 2019 ASA panels, on “Social Theory and Social Progress” (organized by Chris Muller), and “Social Theory and Social Decay” (organized by yours truly).
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