I think you have to control the materials to an extent, but it's important to let the materials have a kind of power for themselves; like the natural power of gravity, if you are painting on a wall, it makes the paint trickle and it drips; there is no reason to fight that.
“I realise that in this undertaking I place myself in a certain opposition to views widely held concerning the mathematical infinite and to opinions frequently defended on the nature of numbers.”