Marcel Duchamp
"The creative act is not performed by the artist alone; the spectator brings the work in contact with the external world by deciphering and interpreting its inner qualifications and thus adds his contribution to the creative act." -Marcel Duchamp
Marcel is described as one of the Fluxus ancestors. I think he fits this description because as mentioned in the article a Fluxus is one that can be an artisit and at the same time an idustrialist or a designer.
On Mariana's page is an example of one of Marcel Duchamps piece. A urinal art that he named fountain.