Blowing through heaven and earth, and in our hearts and the heart of every living thing, is a gigantic breath - a great Cry - which we call God. Plant life wished to continue its motionless sleep next to stagnant waters, but the Cry leapt up within it and violently shook its roots: "Away, let go of the earth, walk!" Had the tree been able to think and judge, it would have cried, "I don't want to. What are you urging me to do? You are demanding the impossible!" But the Cry, without pity, kept shaking its roots and shouting, "Away, let go of the earth, walk!"

It shouted this way for thousands of eons; and lo! as a result of desire and struggle, life escaped the motionless tree and was liberated.

Animals appeared - worms - making themselves at home in water and mud. "We're just fine", they said.
"We have peace and security; we're not budging!"

But the terrible Cry hammered itself pitilessly into their loins. "Leave the mud, stand up, give birth to your betters!"

"We don't want to! We can't!"

"You can't, but I can. Stand up!"

And lo! after thousands of eons, human beings emerged, trembling on their still unsolid legs.
Human beings are centaurs; their equine hoofs are planted in the ground, but their bodies from breast to head are worked on and tormented by the merciless Cry. They have been fighting, again for thousands of eons, to drag themselves, like a sword, out of their animalistic scabbard. They are also fighting - this is their new struggle - to draw themselves out of their human scabbard. The human being calls in despair, "Where can I go: I have reached the pinnacle, beyond is the abyss". And the Cry answers, "I am beyond. Stand up!"

(Nikos Kazantzakis, 'Report to Greco' - slightly adapted)