According to the main theories of the knowledge-based economy (KBE), the recent transformations of capitalism are the origins of a general societal change. Managerial theories consider KBE to be a series of win-win mechanisms that simultaneously favour firms, workers and consumers. The cognitive capitalism theory perceives in the development of cognitive capitalism signs of the formation of a post-capitalist economy. This article discusses the main features of these two theoretical orientations and identifies some core ambivalences in KBE. The relationship between the market and society in KBE is marked by a dialectical process. The former incorporates mechanisms of potential economic valorization generated by informal social relationships. To this end, it must internalize actors, practices and cultures that are partially in conflict with it, given that it must make ever greater attempts to bring the overall process back within the ownership regime. One thus witnesses a reduction of the barriers between firms and society, that can simultaneously engender a more subtle dominance of the former over the latter, or the growth of autonomy, self-organization and peer cooperation among social actors. This second possibility relies entirely upon politics and collective action.