In Germany, in 1941, Germans had a closed system of information. All their information came from one source controlled by government. This caused Germans to be unable to know that Hitler is leading them into a war which they cant possibly win, that Germany's position in the world is weak. They kept believing that Germany is scoring victory after victory, due to government's media creating false stories of success while hiding great failures.
So, what is a closed system of information?
It is a system where learning of information is limited and comes from one or just few sources.
Compare that to the open system of information, which seeks information, but also seeks to increase number of sources so that information can flow in from anywhere freely. Thus, open system of information emcourages debate and exposing to opposite views.
Closed system of information is always harmful to knowledge, and closed system can exist locally, in person's life, even if not widely imposed by government.
Most people stick to few sources of information, or stick to low quality unchecked sources, which makes their knowledge limited.
Knowledge depends on mainly two things:
1. Number of sources
2. Learning ability
Even if learning ability is great, if number of sources is low, then increasing knowledge is much more difficult.
Think of it this way. Imagine if you were blind. The amount of information you could learn would be significantly limited by blindness.
Your senses are your first sources of information. Sources are everything. Senses of other people are also your sources. I have never seen Australia, but thanks to many senses of other people who have seen it and told me about it, I know it exists.
Today, google and AI can be used to learn about many things.
People no longer need to rely on local newspaper or few unchecked conversations, but they have information checked by thousands, maybe even millions of people.
To put it simply, if there are more people who keep information checked, information is more likely to be true. This is not about popularity of information, but about if it remains true while being constantly tested for correctness.
