When we look back at the grotesque decline of Aristotelian scholasticism, or the blinkered single-mindedness of Ptolemaic astronomy, we are reminded of the fate of those ‘orthodox’ marsupials, like the koala, who changed from tree-climbers into tree-clingers. Their hands and feet turned into hooks, their fingers no longer served to pluck fruit and explore objects but degenerated into curved claws with the sole purpose of fixing the animal to the bark of the tree to which it hangs on for dear life.
