"The new architecture has suppressed monotonous repetition and destroyed the equality of two symmetrical halves. It does not allow for continuous repetition. A block of houses is as much a whole as an independent house. Balance and symmetry are two entirely different things. In place of symmetry the new architecture proposes a balanced relationship of unequal parts or parts which differ [in position, proportion, size and materials] in functional character."

"To be white, red, yellow, or black is to be a painter. Today it is not sufficient for the painter to think of colour; he should be colour, feed on colour and transform himself into painting. That is the essential thing. To feel like colour means to carry within oneself the entire range of colours, not as a treasure, but as a trust."

"The artist's studio will be like a glass-bell or a hollow crystal. The painter himself must be white, which is to say, without tragedy or sorrow. The pallet must be of glass; the brush must be square and hard, dust-free and as immaculate as a surgical instrument. Doubtless there is much to learn from a medical laboratory.. .The studio of the modern painter must reflect the ambiance of mountains which are nine thousand feet high and topped with a eternal cap of snow. There the cold kills the microbes."

"The complete and definitive work of art is created beyond one's individuality.. .The universal transcends such a level. Mere spontaneity has never created a work of art which possesses a lasting cultural value. The method leading to universal form is based upon calculations of measure and number."

"One must always paint in opposition to nature, and to one’s own 'mood'. To let oneself go is a weakness, a sort of hysterics. If you are full of red, choose a green or a blue; if you feel like yellow, choose grey or black. In this continuous opposition lies the entire secret of plastic creation.. .To create a great work of art demands self-mortification."

"Forgive me of saying so, but good things just have to grow very slowly. I say this in connection with your [Van Doesburg's] plans.. ..for launching a journal. I do not think that the time is favourable for it. More must be achieved in art in that direction. I hardly know anyone who is really creating art in our style, in other words, art which has arrived.. ..you will have to include in it [in the new journal] what is not consistent with our ideas."

"With regard to the diagonal, too, I am in complete agreement with you [with Theo van Doesburg ]. As soon as it appears together with straight [horizontal and vertical] lines, I believe it should be condemned.. .A while back I started a thing entirely in diamonds [diamond-shape] like this [his sketch in the letter of several diamond-forms]. I have to find out if it's possible: intellectually I'm inclined to say it is. There's something to be said for the idea, because perpendicular and flat lines can be seen everywhere in nature; by using a diagonal line I would be canceling that out. But I'm inclined to say that this cannot be combined with perpendicular and flat lines or with different kinds of slanting lines."