What is a Painting?

It is said ‘there is nothing like comparisons’ because they distort and mislead, but comparisons – or contrasts – between works of art, art movements and the art of different times and countries are one of the fundamental strategies of art history and indeed of comparative anthropology too.

What happens when a double-sided medieval altarpiece is compared with a twentieth-century easel painting? To what extent do they both belong to the category of painting and, if not, are the differences fundamental?

The current Sienna exhibition at the National Gallery, London, displays the Maestà. Usually in fragments at the Museo dell’Opera del Duomo at Siena, it encapsulates fundamental changes in viewing practices that accompanied the emergence of easel painting, and allows shadowy continuities to be detected in Edward Hopper’s enigmatic self-portrait so many centuries later.

Emeritus Professor Richard Read is a Senior Honorary Research Fellow in Art History at the University…