How does the presence and value of knowledge within a society influence its capacity for political invention? This collective work investigates the political vocation of knowledge in ancient Greece. It proceeds in two stages. On the one hand, it examines the figures of knowledge in Ancient Greece - craftsmen, soothsayers, physicians, aedists, poets, philosophers, historians, sophists and astronomers - from the point of view of their public image and the perception of their social role. On the other hand, we need to ask whether the collective practices that conveyed the experience of forming a common body in ancient Greek societies - laughing together in the theatre or making a racket in assemblies, taking part in common rites or deliberating in the Council - manifest forms of knowledge or the representation of knowledge. At the crossroads of these paths, it appears that in ancient Greece, the figures of knowledge owed their social importance to their ability to embody the promise of a service to the public, and that the political form that flourished in certain cities, including Athens, under the name of democracy, is linked to the idea that the people in power are capable of gathering the knowledge necessary to serve themselves.