There were several movements that in the seventies and above all in the eighties of last century discuss the idea of an artist alone and in the loneliness of his/her studio. The authorship was the main question: how to deal with a new collective authorship to legitimize the abandon of the studio for the streets. This movements made a lot of works and the discussion was hard around the question that titles this book. And a new way of artistic work born there: the activism, sometimes closer to daily politics than art practice.