That everything is transitory is merely a simile. Everything we see is a proposal, a possibility, an expedient. The real truth, to begin with, remains invisible beneath the surface. The colors that captivate us are not lighting, but light. The graphic universe consists of light and shadow. The diffused clarity of slightly overcast weather is richer in phenomena than a sunny day. A thin stratum of cloud just before the stars break through. It is difficult to catch and represent this, because the moment is so fleeting. It has to penetrate into our soul. The formal has to fuse with the Weltanschauung ...

We investigate the formal for the sake of expression and of the insights into our soul which are thereby provided. Philosophy, so they say, has a taste for art; at the beginning I was amazed at how much they saw. For I had only been thinking about form, the rest of it had followed by itself. An awakened awareness of "the rest of it" has helped me greatly since then and provided me with greater variability in creation. I was even able to become an illustrator of ideas again, now that I had fought my way through formal problems. And now I no longer saw any abstract art. Only abstraction from the transitory remained. The world was my subject, even though it was not the visible world.

-- Paul Klee The Diaries of Paul Klee ed. Felix Klee

Weltanschauung