The most interesting answer to this question was made (in 1939) by Sprague de Camp in his SF novel Lest Darkness Fall. Time travel: A mousy archaeologist is transported back to Visgothic Rome. He decides to try to prevent the Middle Ages. He does this by inventing the printing press, semaphore, corporations...(and making sure that certain battles are won/lost). Since de Camp was, himself, an archaeologist, the details are accurate (to 1939).

Bottom line is that improved communication and better transmission of information are essential for holding an empire of that size together.

As I have said before, I think that political models may be overturned by new technology, even as fracking has overturned the concept of the amount of petroleum products that are left.

Jan

I with Merlin';s insight would simply tell Marcus Aurelius: "Step down from your throne and restore the republic from the dark side. Cut spending along with taxes and allow free trade to go to work unfettered."
Then I would run and hide to avoid crucifixion.

I'm finding this discussion fascinating and am in the middle of reading the above article. However, I stopped and burst out laughing when I read this line.....

"So, we need something more graphical, easier to understand, especially if we have to show these things to politicians."

Now back to the article. LOL....

Edit: Oh! There is this a little further......

"There remains a problem with politicians. Their attention span is more of the order of thirty seconds or less. But that is another problem." Just too funny.

Ironically, the nail in the coffin of the Roman Empire came when they allowed hordes of refugees to settle in the Italian peninsula. When promised handouts were regarded as unsatisfactory, said refugees overran Rome, took what they wanted, and effectively killed the Roman goose that had been laying the golden eggs they had been subsisting on. The U.S. seems to be headed the same direction. Multiculturalism is a fatal disease.

Mike:

I have always thought that the ability to place into their proper context, when "filling in" the endless "blanks-of-knowledge" in the crossword puzzle of life, to be the hallmark of both intelligence and wisdom.

The failure to properly do so precipitates a perspective that, by endless variability, produces a mental reality that invariably is proven to be "out-of-context."

As a personal example of this, I have concluded that had I been alive in 1933, with the knowledge and values I possessed just a few years ago, I would have concluded, in response to FDR's "gold raid" of 1933, that it (the country) would be quickly(??) finished!

Another example is the very idea of "peak oil" itself. While is it certain that there is a finite amount of hydrocarbons to be found in the earth's crust, the proper context to understand such a postulate, as a practical matter, is determined by Science, Economics, and Politics.

Knowledge is, of course, always primary, but all knowledge is contextual. Reason is, after all, Man's only absolute.

Whether it's population growth, and alarmist fears of associated demands on agriculture, or other resources such as oil have been common. However, free men with cognitive ability and rational self interest innovate for higher productivity. Such innovation renders the bell curve overly simplistic, in the case of oil horizontal drilling and fraccing grew the resource (area under the curve) to a multiple of that imagined by Hrubetz. Though I'm not a historian I suspect Rome was afflicted by the same disease as our modern civilization and so many prior. Societies that embrace free trade then facilitate specialization which compounds value and generates prosperity, which we have in spades. Over time government, as a bureaucracy naturally seeks to grow, and ultimately in cooperation with aligned special interests colludes and coerces to plunder the society, ultimately at the expense of liberty and prosperity.

So...I told the truth, predicted the outcome ..but nobody listened. There were those just as intelligent as me, with as much knowledge, and foresight, but when it came to outlining consequences -- nobody listened. I saw a once mighty republic rotting on the inside and when I showed the danger to its structure - nobody listened. I saw evil men with evil agendas gain power and when I pointed them out, nobody listened. Why didn't they hear me? What does it take to unblind the blind? Aren't these wise men who have attained great stature? If I'm right why won't they see what I see? There must be only one reason that I can discern. I must be insane.
Either that, or the world is.

Thanks for such a thoughtful and insightful essay, especially with the humorous refrences to Druids imaginary and recent.. Even the word exploitation is overcharged. I get that we rarely see the negative feedack or make the fundamental adjustments. What makes me lose sleep is how utterly impotent elected representatives are collectively, who are pettily distracted from any and all well intended sincere 'druid's'..

Liberty and free markets without the corrupt, parasitical central political machine killing the natural miracle of human productivity.

there is none

"Consider the story that the Roman Empire collapsed because the Romans used to drink wine in lead goblets; and so they died of lead poisoning. That has some truth: there is evidence of lead poisoning in ancient Roman skeletons; there are descriptions of lead poisoning in ancient Roman texts. Surely it was a problem, probably even a serious one. But you can't see this story of lead poisoning in isolation; otherwise you neglect everything else: the Roman Empire was not just people drinking wine in lead goblets. Think of a historian of the future who describes the fall of the American Empire as the result of Americans eating hamburgers. That would have some truth and for sure the kind of food that most Americans eat today is - well - we know that it is doing a lot of damage to Americans in general. But you wouldn't say that hamburgers can be the cause of the fall of the American Empire. There is much more to that.

"The same kind of reasoning holds for other "causes" that have been singled out for the fall of Rome. Think, for instance, of climatic change. Also here, there is evidence that the fall of the Roman Empire was accompanied by droughts. That may surely have been a problem for the Romans. But, again, we might fall in the same mistake of a future historian who might attribute the fall of the American Empire - say - to hurricane Katrina. (I have nothing special against the American Empire, it is just that it is the current empire)

"The point that Tainter makes, quite correctly, in his book is that it is hard to see the fall of such a complex thing as an empire as due to a single cause. A complex entity should fall in a complex manner, and I think it is correct. In Tainter's view, societies always face crisis and challenges of various kinds. The answer to these crisis and challenges is to build up structures - say, bureaucratic or military - in response. Each time a crisis is faced and solved, society finds itself with an extra layer of complexity. Now, Tainter says, as complexity increases, the benefit of this extra complexity starts going down - he calls it "the marginal benefit of complexity". That is because complexity has a cost - it costs energy to maintain complex systems. As you keep increasing complexity, this benefit become negative. The cost of complexity overtakes its benefit. At some moment, the burden of these complex structures is so great that the whole society crashes down - it is collapse."

The funny thing about the arithmetic is that it always looks like there is a little bit more until it is all gone all at once.

On the other hand, there is a theory that petroleum is constantly produced as a geophysical phenomenon. See http://www.livescience.com/9404-myste...
and see also
http://www.wnd.com/2008/02/45838/

But petroleum is just one factor. Culture is more important than "stuff." We adapt too easily, and we Americans too easily forget the past. Arab/Islamic terrorism must be pegged to the 1972 Munich Olympics. This is not today's news or yesterday's headlines. It is a significant trend, that, of necessity cannot continue, any more than the Mongol Golden Hoard could conquer Eurasia to the Atlantic Ocean. Even so, in the process, much was destroyed.

One of the foundations for Rome's demise was their dependence on plunder through military conquest. Their "greatness" was similar to the "greatness" of the Egyptians - it was unsustainably built upon slave labor - the worst combination of coercion and looting.

If I were Merlin giving advice to Marcus Aurelius, I would be telling him that Rome was doomed to fall without a wholesale ideological change. I would tell him it wouldn't happen in a day or a year, but it would culminate in a massive societal breakdown.

I find it interesting that he is a professor of chemistry. I'm a technical guy. I find that it's the technical people, not the "poli-sci" types, who ask the tough questions.

The Roman empire fell for the same reason the Pax Britannica and Pax Americana ended -- the empire was unable to maintain its lead in fighting technology over the rest of the world -- thus making it expensive to maintain dominance, and cheap to resist. What we have now is what we saw just before WW1 -- cheap tech that everybody knows about and that lots of sides can and will use. This is why I believe the next world war is close at hand.

I'm not at all sure who will win, but I'm not optimistic. Both the US and Europe have become police states that the average person isn't willing to defend.