“So I had carved one face with hollows curving in-out, in-out, very simple really. I set the timber upright and Frank Stella came in and came over and looked at the chiseling and said it looked good. He turned around to the back of the piece which was uncut – the backside of the timber – and he said, you know that's sculpture too. I supposed what he meant to say was, that cutting was a good idea and the idea of not cutting was good too. But you know, I thought to myself, yes the uncut side is really much better than the cut side. The form of the timber was by no way improved by my cutting into it. From that time, I began to think that the next timbers I get I'm not going to cut. I'm going to combine the timbers; I'm going to use them as cuts in space. I began to look for what I call 'particles”

that is, units which are identical in shape – and finding ways to combine these particles by properties of the individual particles. That is, no gluing and no nailing and no joining.
Source: Artists talks 1969 – 1977, p. 29