'The idea of restriction is perceptible in the shapes I prefer. Point, line and surface, and their spatial relatives – disc, ball, grid, stele, cube, pyramid and wedge – are “dominant” basis shapes to me. My preference for a simple shape does not coincide with a puritan profession of faith; it is my interest in the monumental shape which prefers these simple shapes.’
(Heinz Mack quoted in: D. Honisch, Mack. Sculptures 1953-1986, Dusseldorf 1987, p. 198).