The capability of the artist

SOPHIE: But surely it is a fact about art – regardless of the artist's subject or his intentions – that it celebrates a world which includes itself – I mean, part of what there is to celebrate is the capability of the artist.
MARTELLO: How very confusing.
SOPHIE: I think every artist willy-nilly is celebrating the impulse to paint in general, the imagination to paint something in particular, and the ability to make the painting in question.
MARTELLO: Goodness!
SOPHIE: The more difficult it is to make the painting, the more there is to wonder at. It is not the only thing, but it is one of the things. And since I do not hope to impress you by tying up my own shoelace, why should you hope to have impressed me by painting a row of black strips on a white background?

Tom Stoppard, 'Artist Descending a Staircase' in Plays Two (Faber and Faber, 1996) p. 139

The concrete mixers churn and churn

The concrete mixers churn and churn until only a single row of corn grows between two cities, and is finally ground between their walls.

Tom Stoppard, 'Albert's Bridge' in Plays Two (Faber and Faber, 1996) p. 85