In 1972, Mel Bochner presented Theory of Sculpture Demonstration #6 at Lisson Gallery. In a letter to Nicholas Logsdail he expressed his excitement about visiting London: "The piece I'm going to do is the one I described to you the afternoon we spoke. The only material I will need is 72 medium-sized pebbles [...] I'm sure we won't have any difficulty finding them. I will bring my own piece of chalk."

The use of such materials connects to Bochner's underlying belief that: "art is not understood through intellectual operations, but rather that we intercept the outline of a certain manner of treating (being in) the world." What preoccupies Bochner is the ordering of materials rather than the creation of artefacts. In his own words, "I do not make art, I do art."

Richard Cork's reviewed Bochner's Lisson exhibition in The Evening Standard, 13 April 1972:

"Upstairs at the Lisson, the ‘world’ centres on the demands of three localised surfaces; but downstairs, it ceases to depend on the appearance of the gallery altogether. For Bochner has here set down a number of chalk stones in groups which all multiply to 12: a self-contained procedure entirely independent of any external consideration. At first glance, it would appear that he has agreed to place himself in subservience to the natural form which these stones possessed when he found them on a beach near Brighton. But it soon becomes obvious that the material he has employed is entirely arbitrary. The lucidity of the stones’ various groupings within the order which simple mathematics provides is what really matters.

All are dependent upon the mathematical scheme which brought them into being, certainly, and Bochner stresses the sobriety of that scheme by calling the piece Theory of Sculpture Demonstration #6. But the cerebral dryness which such 
a title suggests is completely counteracted by the wonder of the piece itself, a wonder which helps to explain why Bochner approved of Wittgenstein’s declaration: 'I have to discover the world, to measure things."