[The Constructive idea...] has revealed a universal law that the elements of a visual art such as lines, colours, shapes, possess their own forces of expression independent of any association with the external aspects of the world; that their life and action are self-conditioned psychological phenomena rooted in human nature; that those elements are not chosen by convention by any utilitarian or other reason as words and figures are, they are not merely abstract signs, but they are immediately and organically bound up with human emotions. The revelation of this fundamental law has opened up a vast field in art giving the possibility of expression to those human impulses and emotions which have been neglected.

Naum Gabo (1937) "Editorial", p. 7 as cited in: W. Rotzler (1989) Constructive Concepts-A History of Constructive Art from Cubism to the Present, Rizzoli. - Circle: International Survey of Constructive Art', 1937