What is the author, Finley Hooper's, interpretation of the fall of the Roman Empire?
"The year was 476. For those who demand to know the date Rome fell, that is it. Others will realize that the fall of Rome was not an event but a process. Or, to put it another way, there was no fall at all-ancient Roman civilizations simply became something else, which is called medieval. (It evolved into another civilization, the civilization of the Middle Ages."
Your question pretty much contains the answer -- it's right there at the end of the paragraph. In other words, Hooper is arguing that Rome never fell but that instead, it became something else.
Hooper's not really saying that there wasn't any such thing as the fall of Rome. But what he is saying is that it wasn't the end of all things Roman. Instead, what had been Rome just evolved into something different.
A more recent example that might help...
Russia today still exists even though the Soviet Union has fallen. It's not like the fall of the Soviet Union brought an end to Russian civilization. It just changed it.
That's what Hooper is saying happened to Rome.
In a very real sense, the fall of the Roman Empire occurred when its subjects in western Europe and the Italian peninsula found they could no longer look to the armed might of Rome to protect them and to provide law and order in their communities. To put it in modern day terms, it would be tantamount to having a gang of armed thugs descend on your farm and tell you to pack up and leave within the hour. You tell them, "I'll call the police!" But when you do, no one answers.
Faced with these circumstances, people were forced to look to their own devices. They found the only hope they had lay in going to the most wealthy man in their region and seeking his help, since he already had armed retainers protecting his estates. He agreed to protect them and their holdings, provided they:
1. Sign their land over to him, in exchange for a life estate that would pass to his eldest son upon his death, and to his son's eldest son, et cetera;
2. Provide so many days military service to his protector every year, as circumstances required, and have his sons of military age pledged to the same service;
3. Pay a tax each year to his protector from the yield of his harvest.
Thus, born of military necessity, the feudal system began, with its ever expanding system of liege lords and vassals, which superceded the now absent Roman emperor and his legions.