Joseph Kosuth produced *One and Three Chairs* in New York in 1965; he was a twenty-year-old student that year. There are three elements: an ordinary wooden folding chair stands against the wall; on its left a 1:1 photograph of that same chair, in its own place, is hung; on its right a black-and-white print of the English dictionary definition of 'chair'. All three refer to the same chair — or do they?

Kosuth's question is direct: what is a 'chair' as a work of art? Is it the material object (the chair on the floor), its visual representation (the photograph), or the meaning of the word that names it (the definition)? Classical painting had always worked through the second category — representation; by refusing this, Kosuth places the three side by side at equal weight and leaves the viewer with the question 'which one is the real one'. His answer is 'the idea itself' — the real content of the work is the concept that emerges from this arrangement.

Kosuth set out the same position more openly in his famous essay 'Art After Philosophy' (1969): 'Works of art are analytic propositions. ... Art is only art as art.' This became one of the manifesto-sentences of Conceptual Art, which inherited from Marcel Duchamp and developed in the 1960s alongside Sol LeWitt, Lawrence Weiner, and the Art & Language group.

The work has no 'original' copy — for Kosuth, it consists of a local chair + a photograph of it + a definition; the three elements are set up locally for each exhibition. This property shows how valid the name 'conceptual' is: the objects can change, the concept stays the same.

The version MoMA acquired in 1970 is a copy issued with 'exhibition instructions'.