This thesis investigates the emergence and spread of collectives as a new form of political mobilization in contemporary Brazil. It argues that these collectives reflect a broader process of radicalisation of individualisation, related to what Danilo Martuccelli describes as a singularist society. Although we recognise the relevance of the crisis of democracy and representative system in the emergence of collectives, this thesis argues that the phenomenon goes beyond the political sphere and the debate on democracy, and is part of a broader context of social differentiation, morphological transformations and individualistic values in Brazil. Collectives represent a new form of articulation between the singular and the common, where individualisation and the growing desire for individual autonomy do not result in a withdrawal from the political world or a lack of interest in collective life. The qualitative analysis of interviews with activists from collectives in the city of Rio de Janeiro reveals that these new forms of political mobilization not only reflect the process of radicalised individualisation, but also contribute to the construction of a singularist society. In this society, singularity emerges as a new way of making bonds and making society. Singularism envisages a socialised self-consciousness, in other words, the singularity of individuals can only be affirmed through the recognition of the common. This thesis therefore seeks to broaden the understanding of social transformations in Brazil, linking the radicalisation of individualisation and social differentiation with the multiplication of new forms of political mobilization.