In his massive existential Marxian work, Critique of Dialectical Reason, author Jean-Paul Sartre explains how a seriality of seemingly unrelated people (except through markers of class, ethnicity, or gender, etc.) can come together to form a social force: a group:
[I]n the movement of History, an exploiting class, by tightening its bonds against an enemy and by becoming aware of itself as a unity of individuals in solidarity, shows the exploited classes their material being as a collective and as a point of departure for a constant effort to establish lived bonds of solidarity between its members. There is nothing surprising about this: in this inert quasi-totality, constantly swept by great movements of counter-finality, the historical collectivity, the dialectical law, is at work: the constitution of group (on the basis, of course, of real, material conditions) as an ensemble of solidarities has the dialectical consequence of making it the negation of the rest of the social field, and, as a result, of occasioning, in this field in so far as it is defined as non-grouped, the conditions for an antagonistic grouping (on the basis of scarcity and in divided social systems) (346).
Thus the common praxis, as the totalisation and struggle against a common praxis of the enemy, realises itself in everyone as the new, free efficacity of [their] praxis, as the free intensification of [their] efort; every freedom creates itself laterally as the totalisation of all freedoms, and totalisation comes to it through the others as a lateral dimension of its individuality, in so far as it is freely individual for them. This has nothing to do with the radical transformation of freedom as individual praxis, since the statute of this freedom is to live the very totality of the group as a practical dimension to be realised in and by its individuality. But it is true that there is a new relation between freedoms here, since in every totalisation of the group, the freedom acknowledge themselves to be the same…And the unity of this freedom beneath the shifting multiplicity of the syntheses is itself, and fundamentally, the relation between a negative unity of all (totalisation through annihilation by the enemy) and the negation of this negation to the extent that it is occasioned as totalising and that it produces itself freely on this basis (402-3).
Satre, Jean-Paul. 2004. Edited by Jonathan Ree and translated by Alan Sheridan-Smith. Critique of Dialectical Reason: Volume 1. New York: Verso.