About the educational system, going to school and why the school was invented

Adolphe Ferriere was one of the founders of the progressive education movement.
So basically, the all educational system was changed starting with 1920.
The result of those changes we are able to see them on our everyday life.
Which education they were having before? Were they actually going to school as we do nowdays? Maybe they were studying different things if they were able to build things like this.
What changed so drastically?

Let`s see what this man wrote in one of his books as early as 1920 and maybe we will have a different perspective about school, diplomas and all the educational system in general.