These universal means of expression were discovered in modern painting by a logical and gradual progress toward ever more abstract form and color. On… - Piet Mondrian

I am searching for the proper harmony of rhythm and unchanging proportion, as I wrote in the article. And I cannot tell you how difficult it is. [Mondrian is reacting on Van Doesburg criticism of the strong domination of the regular grid in Mondrian's latest paintings]

In terms of composition the new plasticism is dualistic. Through the exact reconstruction of cosmic relations it is a direct expression of the universal; by its rhythm, by the material reality of its plastic form, it expresses the artist's individual subjectivity. It thus unfolds before us a whole world of universal beauty without thereby renouncing the human element.

And now about architects in general – I have to say it, Does [= Theo van Doesburg ], when 'De Stijl' was founded I left it up to you, but I never did agree with you when you ranked the architects alongside us, alongside our 'N.B.' ( / Neo-Plasticism) I knew then that it would lead to conflict.. .I cannot write about architecture, because I'm not an architect. I mean, I cannot write about the way I write about painting. Later on, though, I will put forward a few ideas.