This new plastic idea will ignore the particulars of appearance, that is to say, natural form and color. On the contrary, it should find its expressi… - Piet Mondrian

Modern man - although a unity of body, mind, and soul - exhibits a changed consciousness: every expression of his life has today a different aspect, that is, an aspect more positively abstract.

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.

The important task of all art is to destroy the static equilibrium by establishing a dynamic one. Non-figurative art demands an attempt of what is a consequence of this task, the destruction of particular form and the construction of a rhythm of mutual relations, of mutual forms, or free lines.. ..the law of the denaturalization of matter is of fundamental importance. In painting, the primary color that is as pure as possible realizes this abstraction of natural color.