Deurbanization was a leading cause of the Dark Ages

Pretty cool comment from user on Reddit (all sourced, and everything):

The Medieval Warming Period that started in the 900s and the discovery of new crops in the New World in the 1500s increased Europe agriculture capacity. This led to more urban living and education which led to the development of new agriculture technologies and even more dense populations (return of urban civilization like Rome). 

The bubonic plague happened in the 1300s which screwed up Europe's economy for a temporary 150 years and in the 1400s you got the Gutenberg Printing Press which lead to 20 million copies of books being printed by 1500 spreading literacy to the masses. 

It took 150 years for Europe's population to recover.  

The Medieval Warm Period, the period from 10th century to about the 14th century in Europe... 

This protection from famine allowed Europe's population to increase, despite the famine in 1315 This increased population contributed to the founding of new towns and an increase in industrial and economic activity during the period.  

A lot can be said about the rise in power of Western Europe once it collected itself from the collapse of the Roman Empire but I dont want to make this too long.

He was refuting the idea that the Catholic Church was behind the European Dark Ages.

The logic actually makes a lot of sense. I wonder if the initial gains from urbanization were greater than the gains now. Is there a diminishing marginal benefit for every person that enters a city?