Gradually I became aware [c. 1914-1918] that Cubism did not accept the logical consequences of its own discoveries; it was not developing abstraction… - Piet Mondrian

For the present at least I shall restrict my work to the ordinary world of the senses, since that is the world in which we still live. But nevertheless art even now form a transition to the finer regions, which perhaps I am incorrect in calling spiritual, for everything that has form is not yet spiritual, as I read somewhere. But it is nonetheless the path of ascension away from matter. Well dear Querido, with many heartfelt wishes, Piet Mondriaan.

I believe that in our period it is definitely necessary that, as far as possible, the paint is applied in pure colours, set next to each other in a pointillist or diffuse manner. This is stated strongly, and yet it relates to the idea which is the basis of meaningful expression in form, as I see it. It seems to me that the clarity of ideas should be accompanied by a clarity of technique.

In his later works Doesburg tried to destroy static expression by diagonal position of his lines. But in this way the feeling of physic equilibrium which is necessary to enjoy a work of art is lost.