This first comprehensive survey of Joseph Kosuth’s work with public media centers on his pioneering project The Second Investigation (1968–74). This indexical work takes the form of anonymous advertisements in media—newspapers, magazines, billboards, television—based on a taxonomy of the world developed in the early nineteenth century by Roget for use in his thesaurus. Marking the start of Kosuth’s sustained engagement with public media, this work anticipated the media orientation of New York postmodernism beginning in the late 1970s.