Fall of Rome
When thinking about Rome, it is easy to see that something, and something very big indeed, was, but no longer is. Something that no longer is has clearly ended, so natural curiosity brings several rather obvious questions to mind. "When did it end?" and "Why did it end?" Asking and attempting to answer these questions has been an industry of writers and historians for a very long time.
One problem with these questions is the deceptive ease with which one can pose them. A much more difficult thing is to define what "Rome" means when we ask when or why "it" fell, or even to clearly state what "fall" means. "Rome" can mean the city itself, the governance of the city and the people in it, the larger cultural world the these people projected around them, the political structure that maintained a widespread system of taxation, communication and military defense, the large number of communities that came to function locally under that system and that were inspired or influenced by cultural influences flowing out from one or more centers, and many more possibilities. Terms such as "Rome" "the Republic" and "the Roman Empire" mask a degree of diversity and decentralization that is foreign to modern people. Furthermore, when something is and later is not, it begs the question to say that something "fell" until the idea of "change" has been fully explored.
From this point of view, talking about the "Fall of Rome" is an example of a "reification fallacy"
"...we should seek perhaps another path and examine the terms we're using to express the problem, especially what we mean when we speak about "Rome falling." Indeed, close study calls the very question into question. "Why did Rome fall?" may be a line of inquiry that has no clear resolution because the question itself is fundamentally flawed. It might be better to ask, 'Did Rome fall?' " - Mark Damen
Dates often proposed for the "fall of Rome" are commonly a thousand years, more or less, after the traditional date for the "birth of Rome", and many changes took place over those ten or so centuries. Nevertheless, there was a time when people began to notice that things had become very different, or that "something" had ended, and it was not long before writers took up the theme. Augustine of Hippo (d. 430 CE) wrote De Civitate Dei contra Paganos as a refutation of the idea that Rome was sacked because the Romans had abandoned their traditional gods. Augustine accurately observes that Rome had suffered reversals long before the Christian era, but in addition to the historical argument, much of De Civitate is taken up with criticisms of the "pagan" world, its culture, religions and institutions, from a Christian viewpoint. Augustine would not be the last writer to use the "fall of Rome" as a vehicle for the advancement of a particular point of view.
"'Why did Rome fall?,' has withstood legions of scholars catapulting answers at it—over 210 different ones at one point—and still it stands unbreached. Few of the suggestions made have left much of an impression. Many involve 'invented histories' of some sort, speaking volumes about the answerer and syllables about the issue." - Mark Damen
The 14th c. CE Italian writer Francesco Petrarca (Petrarch) looked back on the Roman era and gave the term "dark age" to the period that intervened between that time and his own. Whereas Augustine of Hippo was offering an explanation for certain calamities that befell Rome, Petrarch perceived that the entire world of classical literature had ended. Petrarch's conception that the classical world had ended and that the subsequent age was fundamentally different in character established a conceptual framework (the "fall of Rome") that was more or less unchallenged until very recently, notably in the work of Henri Pirenne.
In the modern era, all writers on this topic work in the shadow of Edward Gibbon, whose "The History of the Decline and Fall of the Roman Empire" was published as a series of volumes from 1776 through 1789. Hallmarks of Gibbon's work are the preference for primary literature, its thoroughness, and its rejection of supernatural causes, making it an important statement of Enlightenment methodologies and a precursor to contemporary practice.
His basic research has remained an important framework for the work of others. In his interpretation, Gibbon was a historical progressivist, and his work may also be read as a commentary on the British Empire in which he lived.
"It is the design of this, and of the two succeeding chapters, to describe the prosperous condition of their empire; and afterwards, from the death of Marcus Antoninus, to deduce the most important circumstances of its decline and fall; a revolution which will ever be remembered, and is still felt by the nations of the earth." - Edward Gibbon
From Gibbon to Pirenne
Since the publication of "Decline and Fall", additional historical detail has been added to Gibbon's framework, primarily through the contributions of archaeology and the related field of epigraphy. Gibbon's fundamental factual framework has stood unchanged in its essentials. Subsequent editions, updating and commenting on Gibbon's original include those by J.B. Bury (1909-1914), Hugh Trevor-Roper (1993-1994) and David Womersley (1994). The interpretation of these facts, however, has provided an opportunity for expression of a very wide range of views. When attempting to explain "why Rome fell" authors often provide a view of the concerns of their own time, rather than an objective account of Rome.
"Why did the Roman Empire in the West collapse? It has remained a vital question because each age has seen in the tale of Rome's fall something significant and relevant to its own situation." - Donald Kagan
Michael Rostovtzeff (1870 - 1952)
Tenney Frank (1876 - 1939)
A. E. R. Boak (1888-1962)
Pirenne and beyond
Henri Pirenne (1862 - 1935) 
In popular culture
Because of the immense scope and popular appeal of the "fall of Rome", it is possible for specious arguments to gain at least popular acceptance. An example is the role of lead toxicity. It is certainly true that lead is toxic and that lead was used by Romans as water pipes and in cooking vessels, so the claim that "lead poisoning contributed to the decline of the Roman empire"
is irrefutable in a strictly logical sense, but it is also irrelevant, as the contribution of lead poisoning was either non-existent or trivial compared to other causes.
The real problem is with the word "contribute", a so-called "weasel word"
that fails to specify the magnitude of the contribution, thus making the position proof from logical assault. In spite of this flaw, many specious arguments remain alive in the popular imagination. 
The topic of explaining the fall of Rome continues to fill the lives of scholars and to trouble the lives of students. New titles are published regularly , and the "fall of Rome" provides a heavy weight for each generation of students to use to exercise their mental muscles as they attempt to master history, academic writing and critical thinking.
- ↑ Knox, E.L. (n.d.). Why Rome Fell . . . and why it doesn't matter. Boise State University.
- ↑ Wikipedia: Reification fallacy.
- ↑ 3.1 3.2 Damen, M. (2008?). 1320: History and Civilization
- ↑ Anderson, B. (1997 The Decline and Fall of Footnotes in Stanford Magazine.
- ↑ Gibbon, E. (1776). The Decline and Fall of the Roman Empire
- ↑ Kagan, D. (1962). Problems in European Civilization: Decline and Fall of the Roman Empire. Why Did It Collapse?
- ↑ Pirenne, H. (1939). Mohammed and Charlemagne. New York
- ↑ Nriagu, J. (1983). "Saturnine Gout Among Roman Aristocrats: Did Lead Poisoning Contribute to the Fall of the Empire?", New England Journal of Medicine, 308, 660-663
- ↑ See Encyclopedia Romana: Lead Poisoning and Rome for a closely reasoned refutation of Nriagu.
- ↑ Wikipedia: Weasel word
- ↑ See for example Fall of the Roman Empire at rome.info, a travel guide.
- ↑ O'Donnell, J. (2005) Review of Peter Heather, "The Fall of the Roman Empire: A New History" and Bryan Ward-Perkins, "The Fall of Rome and the End of Civilization",a Bryn Mawr Classical Review of two recent efforts illustrates the point.
- ↑ John Brown University Undergraduate Journal: The Fall of the Roman Empire by Jacob Little. A nice piece of undergraduate writing which demonstrates the cultural biases of the writer.