Where does our current obsession for interactivity stem from? After the consumer society and the communication era, does art still contribute to the emergence of a rational society? Nicolas Bourriaud attempts to renew our approach toward contemporary art by getting as close as possible to the artists' works, and by revealing the principles that structure their thoughts: an aesthetic of the inter-human, of the encounter; of proximity, of resisting social formatting. The aim of his essay is to produce the tools to enable us to understand the evolution of today's art. We meet Felix Gonzalez-Torres and Louis Althusser, Rirkrit Tiravanija or Félix Guattari, along with most of today's practising creative artists.