Resumen: Scholars are increasingly turning their attention to cooperative firms, characterized by worker ownership and management, as a way for organizations to address the economic, societal and environmental problems posed by corporate capitalism. This renewed interest stems from the potential of cooperatives to foster an alternative economic system grounded in democratic, solidary and environmentally conscious values. However, previous studies have not provided a comprehensive analysis of the contradictory nature of cooperatives within a broader inter‐organizational and systemic framework. Applying a Marxian perspective on paradoxes and dialectics, we theorize that cooperative firms operating within capitalist economies must navigate the ‘solidarity paradox’ – the inherent impossibility of overcoming market competition through partial and limited solidarity strategies. Drawing on an examination of the Mondragon cooperative group, we illustrate how such a fundamental contradiction manifests itself into multiple paradoxes that are interwoven, mutually constituted and inseparable. The article contributes to critical management scholarship on cooperatives by offering a deeper understanding of how these organizations perpetuate systemic capitalist patterns. It also contributes to paradox and dialectics scholarship by theorizing that paradoxes are not timeless and universal but the result of persistent contradictions inherent to historically contingent organizational forms. Idioma: Inglés DOI: 10.1111/joms.13175 Año: 2024 Publicado en: JOURNAL OF MANAGEMENT STUDIES (2024), [31 pp.] ISSN: 0022-2380 Financiación: info:eu-repo/grantAgreement/ES/UZ-IBERCAJA/JIUZ-2022-CSJ-03 Tipo y forma: Artículo (Versión definitiva)