>>40410
>have to say (who?) in here.

Everybody, I can't even think of an individual.

>be it mathematics, engineering, free thinking, religious tolerance, geography I think pretty much everything regress,

Maths was still studied in this era although much of what they studied from was Arabic(not Roman). Engineering is a funny old thing, there was not so much history of it in Europe to begin with, they didn't have thou thousands upon thousands of years of Stone structures that the Middle east and such did. However, The Italian states were actually still making large stone structures and the North did a bit it just had not developed so much but that development largely came internally. There was no Free thinking in Rome, Religion was only tolerated so long as it didn't interfere with the empire in anyway(also keep in mind that Ancient religion is fundamentally different to modern religion in that modern religions often state quite clearly that they are the one faith and nobody is to follow another). Even Geography, much of it is tied to location and trade, it's the reason that Arabs had such a good grasp of it.

>not to mention history is not linear, there can be golden ages and dark ages it's not a straight line like for example marx suggests

Technology and idea wise it kind of is at least in general it is.

>this pretty much disregard every other regression.

Not really, as I said, it's not like antiquity had an abundance of it and they were still copying and using ancient literature.