Erlir - I think you were agreeing with me without realizing it. 
I think one of the main reasons parents shelter their children from “inappropriate material” is because they think that’s just what good parents do. Can you imagine how you as a parent would feel if your kid picked up on a whole vocabulary of foul language and started spurting it out at school? Can you imagine the judgment and presumptions teachers and other parents would make? There’s motivation there for the parents’ own wellbeing, not just the children.
I had the opportunity again today to look through a large pile of grades 3 through 6 American school text books; science, maths, history, society, languages.
There are a few things I would like to mention.
The science, history and society texts are just farce. There is no better word for books so heavy with propaganda and so light on information. But this is only the most superficial of considerations.
Students are lead by the most narrow lines of information, and asked to draw conclusions such as,
[size=140]Why did the Great Depression happen?[/size]
As though any student could possibly formulate any answer other than that just given in the above paragraph. But this is straight forward. What is more dangerous is the Montessori method and it’s friends. Although having the appearance of giving the students the freedom to discover their own conclusions, this is not so at all; the student is set up by the informations and questions to discover exactly the lesson that the teacher has so cunningly laid for them. Critical thinking is not. The student may be asked to answer [size=140]What is a law you followed today? How does that law help your community?[/size] But never, “What laws are unjust?” Or “How does law harm your community?” Young people in schools are not asked serious CRITICAL questions; and what is critical thinking without criticism? But even this is only a surface consideration.
Young children carry the most eccentric ideas imaginable about the how and why of things; miscomprehensions of the meanings of words and so on; but by the age of about grade three and four, these idiosyncratic ways of thinking are quite eliminated. This is by lessons such as [size=140]Why do people work?[/size] [size=140]What is money?[/size] [size=140]What do taxes pay for?[/size] [size=140]Which child is following the rules?[/size] Children need to have the very most basic things framed for them, things adults assume and except for perhaps philosophers have long since taken for granted.
Quite a bit of the material is devoted to teaching children how to think in such and such a way. Just to give one of many examples,
This resourse map has little meaning; it is not accurate, and no student would find it interesting. But a child needs to be instructed to think of a country first of all, and then to think of a country in terms of its resources; to think like a mass industrialist right from the age of ten and eleven.
The gross distortion of facts is troubling but really not so interesting. The lack of information and the way that children are lead to conclusions also is troubling but not as dreadful as what is the most important function of a child’s education, that being to eradicate eccentric and idiosyncratic thinking, the sort of ideas that decades later philosophy students say to themselves, I remember thinking that when I was nine years old. A student has the odd currencies of his mind changed for the standard coinage. This is the deepest and scariest part of education; lessons that we learnt so long ago we long since forgot ever learning them or that we used to think some other way in the primitive space of the mind before learning the ABCs.
[size=140]A noun is a person, place or thing.[/size] At first a child has a hard time learning this because upstairs and downstairs are adverbs. Few adults ever question this or read Geach’s criticism of the traditional definition of a noun.