People who reject transcendent authority can no longer persuade one another through rational arguments; everything is reduced to personal opinion. Debates about ideas thus degenerate into power struggles; we're left with no moral standard by which to measure the common good. For that matter, how can there be a 'common good' without an objective standard of truth?
The medieval ideas of the "wild wood" was like a cupboard into which they stuffed everything they were afraid of - Wodwose, Green Men, demons, strange creatures - and of course the most fearful thing of all- wild women and their sexuality!