Kandinsky on Abstract Art

"The impossibility and, in art, the uselessness of attempting to copy an object exactly, the desire to give the object full
expression, are the impulses which drive the artist away from"literal" colouring to purely artistic aims…

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."

...Part II, About Painting, The Psychological Working of Color, by Wassily Kandinsky