I’ve thought about this issue before too. The way I see it is that the ruling class produces propaganda to justify standing on the backs of their fellow humans. Then the next generation absorbs this propaganda as if it were, at least in part, fact. They then develop more propaganda based on the old propaganda. This continues on and on as the empire grows. Then, when the empire begins to decline, they keep acting based on the propaganda that has been stuffed into every weak point to shore it up. Except now the propaganda is far out of alignment with the material conditions because they’ve changed. So their perspectives are out of alignment with reality. They are making what appear to them to be rational decisions based on their highly propagandized perspectives. They continue to rationally respond as their conditions demand, but what they think is rational is actually a manufactured fiction. I hope I was able to explain this well enough.