A quote from Bernard Lonergan, SJ:
A civilization in decline digs its own grave with relentless consistency. It cannot be argued out of its self-destructive ways, for argument has a major theoretical premise, theoretical premises are asked to conform to matters of fact, and the facts in the situation produced by decline more and more are the absurdities that proceed from inattention, oversight, unreasonableness, and irresponsibility.
from Method in Theology, 1972
I haven’t read the book, the quote turned up on Facebook.
In other words, a declining civilization is stuck in a self re-enforcing circle: bad ideas create bad facts on the ground, which create more bad ideas. There is no getting out of it. The only possible arguments to be made are the ones that encourage more self-destructive behavior.
Whenever I read about the Roman Empire, I am always struck about how they simply did not have the theoretical tools to understand their own decline. Yes, in part it was moral: Romans in the West kept getting softer and more impractical; but it was also economic, environmental and geopolitical and they simply could not understand what was happening to them.
Sometimes I have a feeling that for all our vaunted knowledge, we are not much better off than they were. Here is a chilling possibility: we probably have all the data we need at hand to understand our own decline, but not the mental categories to interpret it. What our mental categories tell us to do is to keep digging the hole we are in, and the minority arguments against the direction of society also lack the proper interpretive categories. Nobody knows what is going on, and they all argue about useless things.