The paper considers the recent critical and sceptical perspectives of social sciences on the Third sector. Above all, it reflects on the difficulty in identifying specificities of this supposed sector of contemporary society. Starting from this scenario, the author introduces the perspective of relational sociology as a possible way of defining a specificity of the sector, on the basis of the different \u2018semantics of social relation\u2019. In the second part of the work, a review of ten years of empirical research on the third sector, conducted in Italy, by a team of relational sociologists, puts the theory to the test finding both confirmations and disconfirmations
