Well, almost all of the work of Greek philosophers and their science and philosophy achievements were in Catholic Europe completely forgotten and actively censored for centuries. Fantastic Roman infrastructure, aqueducts, running water inside the multi-storey buildings and huge sewage systems were completely neglected - people completely lost the Antic ideas of hygiene - resulting in horrible sanitary conditions as newly built cities lacked any sanitary infrastructure. Even rich people lived like that, almost no castle even after the middle age had a sewage system, nor running water. They used wells for water and dropped sewage in front of houses, on the streets directly.
Now, they didn't return to stone age of course, practical tools and technologies that were a part of common knowledge remained in use, but many advanced engineering skills were lost. Also the society drastically changed, it fell into religious fanaticism and extreme conservatism - which is the main reason why it was called the dark age actually.
> Well, almost all of the work of Greek philosophers and their science and philosophy achievements were in Catholic Europe completely forgotten and actively censored for centuries.
While less available they were still known and studied and certainly not censored. Neo-Platonist and Aristotelian thought was very influential in the Post-Antiquity and Early-Medieval time periods: see the Desert Fathers and the Scholastics. And that's not even talking about the fact that the Byzantines were there the entire time; most "Renaissance" ideas had the origins in Medieval Byzantine thought.
As for hygiene, feel free to look at the Wikipedia article for it[1]: the sewers weren't that effective, people still threw rubbish in the streets, and the bathhouses were cesspools of disease. And that's not talking about that fact that Roman sewage and hygiene was just that: Roman. It's not like the Roman Empire was some golden age where every city in Europe lived like that. Most places it was just as dirty and filthy.
> Also the society drastically changed, it fell into religious fanaticism and extreme conservatism - which is the main reason why it was called the dark age actually.
It went from being under the control of an autocratic emperor to...being under the control of an autocratic feudal lord. Saying it "fell into [..] conservatism" seems a bit off when it really just traded one man for many. Religious fanaticism I won't bother talking about (why does everyone think people suddenly became more religious after Rome?). As for the term dark ages, that's just a term Petrarch alluded to the time period with, which was then later used in reference to the fewer historical records we have for the time period. It made no reference to religious fanaticism or conservatism.
You’re not arguing against a competing view of history.
You are arguing against an ideology.
Save your breath.
This is their view of history:
Ancient Rome was enlightened. Then Christianity destroyed all the worlds great accomplishments. Then, Galileo showed everyone who was boss.
Oh yeah... a corollary to this version: Islam was as nearly enlightened as Rome and would have ushered in an age of elegant sophistication but for the no-good Crusaders.
So sad...
In reality, Ancient Rome was a brutal slave-based society where life was cheap, religious fanaticism was rampant, children were disposable, and death was glorified.
Given a choice of being an average inhabitant of the Roman Empire or an average inhabitant of medieval Europe, only the truly ignorant would choose the former.
> Religious fanaticism I won't bother talking about
How would you characterize things like Children's crusades (and Crusades in general), Holy Inquisition, hard prosecution of every other religion and even other Christian fractions like e.g. Cathars?
And let's keep Byzantine out of this, I was talking about West specifically. West which experienced a significant population decline, wars, plagues, and which between 1st and 10th century produced very little of anything new. No big science discoveries, very limited architecture pieces - almost all churches, the (single) religion becoming the absolute focus of any artistic and cultural life. The remaining books and educated people were forced into self-censorship, as many philosophical ideas were considered as blasphemes, and Church positioned itself as one and only gatekeeper to knowledge.
If it was like you're claiming then West Europeans wouldn't need Arabic books to learn about ancient Greece achievements (as they had), and there wouldn't be an explosion of culture and education and book production as it was after fall of Cordoba and Toledo back into the hands of Christians. Arabic library of Cordoba is claimed to have had 400 thousands books, which was estimated to be more than what the whole Western Europe had at the time. In just a few decades the number of books in Europe multiplied many times, first Universities started to be created, things started moving. Just look at the dates when the first Universities were created in Europe: Bologna and Oxford 11th century, Paris and Salamanca 12th century, etc. It's not coincidence, they regained access to the Ancient sources that were lost before and that put them back in the saddle. If all the knowledge was preserved and readily available all the time as you've claimed, this peak would never be that drastic. And also there wouldn't be "a lack of historical records" if people were writing down the facts more - instead of concentrating on religious discussions.
And yes, Francesco Petrarca was the first known to use the term Dark Ages, and he specifically meant that because of the lack of great works and authors of the Classical period. But he wasn't talking about "the fewer historical records" - he freaking lived in that time and was talking about his own feelings that the culture of his time sucks. And great that he did, because he helped change that later.
And the term certainly wasn't used only by him, and not only in that context.
Now, they didn't return to stone age of course, practical tools and technologies that were a part of common knowledge remained in use, but many advanced engineering skills were lost. Also the society drastically changed, it fell into religious fanaticism and extreme conservatism - which is the main reason why it was called the dark age actually.