This project, conducted with Scott Viallet-Thevenin (research associate at the CSO (Center on the Sociology of Organizations)), examines the social structures of the State, in the form of civil service bodies, and more particularly the senior civil service. The discreet role of "large bodies" is regularly highlighted in the press, but the actual definition of these large bodies is often unclear. This spontaneous sociology insists on three characteristics: 1) the large bodies form a small elite, socially selected and academically recognized; 2) they constitute informal and invisible networks of mutual aid at the heart of the State system; 3) they reflect a cultural characteristic of the French State, which is old, centralized, and able to impose its views on the large companies within the private sector. We hypothesize that this threefold representation is the product of a simplified generalization of how the largest bodies function across the the senior civil service as a whole.