Imagine, hypothetically, that you wanted the regime to succeed. Would you recommend Cathedralization? Cynically considered, the track record is, at least, not bad. Planetary dominion is not to be sniffed at. (Suggestions in this direction are not unknown, even in XS comment threads.)
The Cathedral, defined with this question in mind, is the subsumption of politics into propaganda. It tends — as it develops — to convert all administrative problems into public relations challenges. A solution — actual or prospective — is a successful management of perceptions.
For the mature Cathedral, a crisis takes the consistent form: This looks bad. It is not merely stupid. As Spandrell recently observes, in comments on power, “… power isn’t born out of the barrel of a gun. Power is born out of the ability to have people with guns do what you tell them.” (XS note.) The question of legitimacy is, in a real sense, fundamental, when politics sets the boundaries of the cosmos under consideration. (So Cathedralism is also the hypertrophy of politics, to the point where a reality outside it loses all credibility.)
Is your civilization decaying? Then you need to persuade people that it is not. If there still seems to be a mismatch between problem and solution here, Cathedralism has not entirely consumed your brain. To speculate (confidently) further — you’re not a senior power-broker in a modern Western state. You’re even, from a certain perspective, a fossil.
Cathedralism works, in its own terms, as long as there are no definite limits to the efficacy of propaganda. To pose the issue at a comparatively shallow level, if the political response to a crisis simply is the crisis, and that response can be effectively controlled (through propaganda, broadly conceived), then the Cathedral commands an indisputable practical wisdom. It would be sensible to go long on the thing.
If however (imagine this, if you still can) manipulation of the response to crisis is actually a suppression of the feedback required to really tackle the crisis, then an altogether different story is unfolding.
Is reality subordinated to the Cathedral because — and exactly so far as — ‘the people’ are? That is the question.
ADDED: Deeply relevant.