Class Discussion Question Brecht

Galileo's time, where the church controlled much of the information that was accessible, and Brecht's time in Nazi Germany draw many parallels between each other. One striking similarity is the opposition to change. The church in the 17th century forced people to discredit their own research and even executed those that opposed their view on the world and how it worked. Nazi Germany was known for its censorship of news and scientific research and making the same threats that the church had done centuries before. 

Why do these people in power during these specific time periods hinder the expansion of research and discussion when some of these findings could greatly benefit many people in society? Are they content with their current ideology and belief system or do they fear that revealing such knowledge to the masses will cause chaos and confusion?