"religion is the opiate of the masses" - Karl Marx
History technology science medicine - et al , were all present and understood - studied by the monks and scholars withing the monasteries and abbeys of the
christian world. Not forgotten, just not taught to the masses , the social and politcal society of the day needed an ignorant population for simpler subjugation.
generally that why many things were "rediscovered" , as the old order bagan to recede in the wake of such political and religious upheavel of the absolution of the monasteries under H
VIII, the reformations etc
The key was access to information-They controlled the information and they controlled who
had access to it, they controlled how to read and how to write-it was denied by virtue of ignorance and social order
As above , with social and political upheavel of the late middle ages , scholars thinkers merchants bankers industrialists etc gave birth to the romantcism and practical reaslisation that was the renaissance. ie da vinci
had access to "galens" etc etc
The irony is that without the zealous concealement of such knowledge and their meticulous efforts to both transcribe, and preserve texts , the majority of it "would" ahve been lost to time and ignorance.
this has enormous subject matter to cover, i have tried in just a few paragraphs, and impossible task , but there you go :)
