Now, do you ever wonder how it is that you can often read such things and find them to be so prescient, today? Do you understand why that is? Well, for one, it’s because they understood practical politics; they understood human propensity to be driven by fear above all else; and they understood human propensity to seek authority ("easy answers") outside of its own capacity to reason.
They also understood that the only defense against such civilization decline was adherence to a set of principles. Unfortunately, they didn’t go far enough (though they went as far as they could, in the context of an authoritarian state — which is indeed what they established).
The lesson to take away from that is there’s simply no way to establish an ultimately all-powerful institution ("checks & balances" only slow things down) like a state, along with its constitution that, regardless of its seeming "reasonable" nature, is still an imposition upon men. In the end, the core differences between the state they established and the state we have today is primarily degree, not principle. In terms of the logic of human nature applied to political power, everything has marched along pretty much as I’m sure some of the more enlightened amongst these wise men forecast in their warnings.