Starting from the analysis of the extensive, varied area knows as the third sector recently conduced by Donati and Colozzi, the author calls attention to three potential points of convergence (cultural, structural and functional) with the basic tents of socio-legal research as already elaborated and developed since the beginning of the last century. Focusing in particular, in this context, on analaysing the spontaneous formation of groupings independent of the state, the essay then sets out to identify certain topics that might enable the complex apparatus of sociology of law theory to delimit and interpret the third sector, thus also identifying the role it is capable of playing in contemporary societies, without getting involved in the state-market axis