chagalov:

The concept itself came from the material, from the nature of material. His (Brancusi’s) work came from the creativity of the hand, how you hold a saw, what kind of a saw you hold… It was not a question merely of the result but of the process.

Quoted in: Anna C. Chave, Brancusi and Noguchi: Towards “A Larger Definition of Sculpture” - Full text (pdf) as well as some others available on Anna Chave Website