When people accept futility and the absurd as normal, the culture is decadent.
--Jacques Barzun, From Dawn to Decadence
The basic idea seems to be that when the West was a growing and thriving society, people had faith in their culture and institutions. They believed that things worked, or could be made to work, or were as God intended. Now they believe no such thing. In shorthand, I suppose, the acronym SNAFU would be the clearest expression of our own decadence. He continues:
But why should the story [of the West] come to an end? It doesn’t, of course, in the literal sense of stoppage or total ruin. All that is meant by Decadence is “falling off.” It implies in those who live in such a time no loss of energy or talent or moral sense. On the contrary, it is a very active time, full of deep concerns, but pecularily restless, for it sees no clear lines of advance. The loss if faces is that of Possibility. The forms of art as of life seem exhausted, the stages of development have been run through. Institutions function painfully. Repetition and frustration are the intolerable result. Boredom and fatigue are great historical forces.
It will be asked, how does the historian know when Decadence sets in? By the open confessions of malaise, by the search in all directions for a new faith or faiths.