Abstract The relationship between contemporary art in the tradition of the avant-garde, politics and the public domain is the subject of this article. By looking at critical social theory, especially the work of Chantal Mouffe, the relationship between politics and the public sphere will be explored. Via the work of Paulo Virno and Niklas Luhmann, I will get more grip on avant-garde art’s functioning in society and its relationship with politics and the public sphere. By discussing the insights of these theorists it will be argued that the contemporary art world – as a sphere of concrete museums, biennials, exhibitions, etc. form a public sphere of many different singularities, artistic styles and sometimes even conflicting paradigms and cultures. Contrary to the classic Habermasian view (1989) this public sphere is seen as an agonistic one in which a multitude of conflicting voices coexist. Contemporary art in the tradition of the avant-garde time and again posits a ‘dismeasure’ within a culture and will therefore take up a minority position within a society. This does however allow this art scene to become a model for a specific interpretation of democracy, especially a minority democracy, in which collective support for emerging singular voices has to be gained time and again. The argumentation needed to grow from the singular base to a somewhat or very much larger collective base is the core of a minority democracy within an agonistic public sphere. This view is at odds with the concept of public sphere mostly held nowadays according to the rules of the dominant liberal representative democracy, which, after all, found its legitimacy on anonymous numbers (the majority of votes) and the third way of compromise. But also hegemonic political regimes of today, such as neo-liberalism and the upcoming neo-nationalism, are concerned about agonistic spheres, because from their perspective they are still difficult to control. It is one of the reasons why such ideologies hardly know how to respond to contemporary avant-garde art.