I think it was Marc Widdowson who wrote about the loss of the ability to restrain madmen in declining civilizations. He illustrated this with Roman philosophers who advocated dropping their pants and masturbating in the streets because it was "natural" and therefore "wrong to inhibit in any way." Socrates himself defecated and urinated in public because he said it was a "natural function" of the body. After a while, people just stop noticing ... caring ... acting.
In the end, every declining civilization simply becomes a circus of madmen who are unrestrained - it could be regarded as the ultimate expression of "multiculturalism." All norms of civilized behaviour vanish and give way to a freeform chaos of schizophrenic histrionics. The lunatics act at random and do whatever they please and the citizens just stand mute and frozen, unable to even condemn such things or remember why they were objectionable.