'The desire to create art not in imitation of nature, but parallel to it, was nothing new for Paul Klee’s time; it had been the declared intention already of Paul Cézanne. In a speech given in 1924 at the opening of an exhibition of modern art in Jena, Klee compared the artist to a tree trunk that gathers from the depths and channels its substance to the treetop, which for him was the work of art. As Klee observed, no one would "expect a tree to form its crown in exactly the same way as its roots"; rather, he argued for freedom for art, whose response to natural prototypes should not have to constitute a "scientific check on fidelity to nature." Klee’s desire was to make works prompted not merely by the outward appearance of nature, but an art which, like creation itself, would emanate from an inner, life-giving creative process that in turn would remain vital within the work.'
(A. Daemgen in, The Klee Universe, Ostfildern, 2008, p. 207)