The development of plastic art is determined by the will to visualize. Art of the past represented the subjective vision of 'naturalistic relationships'. Neoplasticism embodies a subjective vision of 'plastic relationships... Pure thought, which does not signify a concept derived from natural phenomena but which is contained in numbers, measures, relationships and abstract lines, is revealed conceptually (as Reason) by Chinese, Greek and German philosophy, and aesthetically by contemporary Neoplasticism.

in his art-review, published in: 'Thought – Vision – Creation', in De Stijl Vol ll, 2 December 1918; as quoted in 'Theo van Doesburg', Joost Baljeu, Studio Vista, London 1974, pp. 108-109