Solidarity’s object—the salient, group-delineating feature—is its chosen cause.
Solidarity with [a person or people] against [a problem both/all people want to overcome].
Solidarity is not a dyadic relationship: a relationship between a person qua subject and a person qua object (x2), where the two people’s roles are defined only in relation to one another.
Solidarity is a shared relationship that two (or more) people–subjects have together with the object(-ive), like that of team– or band–mates.
It’s the difference between a proper friend and a ‘work friend’ who knows most intimate details of your life, yet you never spend time with them outside of work.
Obligations of solidarity are joint and non–transmittable to the individual. Thus, they are non-reciprocal.
Solidarity’s practices—i.e., collective(–self) defense—are a form of mutual cooperation, borne of the interdependence connecting all political subjects.
A song’s composition determines what roles/participation are needed to play it—what skills bandmates need, what instruments are required, etc. And each song determines its own level of fixity: for instance, you could realistically substitute a banjo for a guitar, but I struggle to think of an instrument (or even an instrument ensemble) that could possibly replace a gamelan—an instrument with a unique playing style and notation system.
Analogously, the particular material circumstances (the ‘problem’ or injustice) that defines the relevant solidarity doesn’t simply identify a group, it constitutes the form of solidarity itself—detailing the required roles, skills, leverage, tools, etc., and the particular way those roles must relate for successfully overcoming/changing the material circumstances.
Participants in solidarity are devoted to their cause, not loyal to their fellow participants.
Devotion is a commitment to one’s sacred values.
Solidarity’s unity is deeply, viscerally affective. Through solidarity’s embodied practices, solidary subjects realize (in the technical sense of making a concept real) the interdependence that unifies them.
The interdependence I refer to here is not merely economic interdependence but political (read: existential) and thus, emotional, insofar as it needs to be felt.
Solidarity's unifying mechanism is its shared moral understanding of the relevant problem that gives it meaning as an injustice/wrong.
Cohering a shared moral understanding means that solidarity turns mere dependence (or reliance) into trust by providing a shared foundation from which an attitude of optimism about the others’ responsiveness to that dependence can develop.
Solidarity’s ends are indeterminate, as those opposed to the solidarity determine what is needed; acts of solidarity are reactions. Thus, solidarity requires constant experimentation—playing with the roles one can fill and the tools one can use.
Solidarity is inherently trans—transgressive, transformative, transgender, transnational, or otherwise. By embracing the opacity and indeterminacy of their own collective will, it resists the identification inherent in gender norms, the juridical capture of the nation–state and its borders, etc.
Solidarity functions as a kind of play with identity—allowing us to become other, in the most robust way possible.