The transition from art brut to art without boundaries reflects a century of radical aesthetic, sociological and institutional changes that gave rise to a fundamental questioning about what is the definition of art and the artist’s status, and indeed when can a creation be legitimately called a work of art. This publication concentrates on the roles of three emblematic protagonists in the field of asylum, brut and outsider art: Hans Prinzhorn, Jean Dubuffet and Harald Szeemann. Three leading actors who contributed to the theorization and advancement of the perception of artworks often merely apprehended through the prism of the psychic and/or social conditions of the author.