The Encyclopedia of Aesthetics 2nd Ed.
From the late nineteenth century to the 1950s one of the main foci of aesthetic inquiry was the attempt to develop definitions of art and such related concepts as visual art, music, tragedy, beauty, and metaphor. Clive Bell (1958) famously stated that either all works of visual art have some common quality or when we speak of “work of art” we speak nonsense. DeWitt H. Parker (1939) argued more generally that the assumption underlying every philosophy of art is the existence of some common nature present in all the arts. This search for a common quality or nature of art was generally taken to be a form of essentialism.
Tom Leddy. "Anti-Essentialism" The Encyclopedia of Aesthetics 2nd Ed. (2014).