Houses and trees [in and around Murnau] made hardly any impression on my thoughts. I used the palette knife to spread lines and splashes of paint on … - Wassily Kandinsky

You mention the circle and I agree with your definition.. ..why does the circle fascinates me? It is (1) the most modern form, but asserts itself unconditionally, (2) a precise but inexhaustible variable, (3) simultaneously stable and unstable, (4) simultaneously loud and soft, (5) a single tension that caries countless tensions within it. The circle is the synthesis of the greatest oppositions. It combines the concentric and the eccentric in a single form, and in balance. Of the three primary forms (triangle, square, circle), it points most clearly to the fourth dimension.

Painting is a thundering conflict of different worlds, which in and out of the battle with one another are intended to create the new world, which is called the world of art. Each work arises technically in a way similar to that in which the cosmos arose – through catastrophes, which from the chaotic roaring of the instruments finally create a symphony, the music of the spheres. The creation of the work is the creation of worlds.

The more abstract is form, the more clear and direct is its appeal. In any composition the material side may be more or less omitted in proportion as the forms used are more or less material, and for them substituted pure abstractions, or largely dematerialized objects. The more an artist uses these abstracted forms, the deeper and more confidently will he advance into the kingdom of the abstract. And after him will follow the gazer at his pictures, who also will have gradually acquired a greater familiarity with the language of that kingdom. Must we then abandon utterly all material objects and paint solely in abstractions? The problem of harmonizing the appeal of the material and the non-material shows us the answer to this question. As every word spoken rouses an inner vibration, so likewise does every object represented. To deprive oneself of this possibility is to limit one's powers of expression. That is at any rate the case at present. But besides this answer to the question, there is another, and one which art can always employ to any question beginning with "must": There is no "must" in art, because art is free.