Tearing pages or corners of pages from books is a metaphor signalizes illness. The Baby (the patient) shows her parents there is something wrong with their treatment of the illness i.e. parental education. In stead of understanding the symptom which is a semiotic language communicated by the Baby (since it can’t speak to explain what’s wrong) the father reacts by imposing punishment as part of his education. This is a general metaphor and can be applied to all areas of human life including medicine. Medical doctors/educators often don’t understand the symptoms and apply the wrong treatment. You go for an illness and get another one.( traditional education/medicine and side effects).
Parents are supposed to understand or at least to try to understand why the Baby tears pages and goes on tearing pages in spite of punishment. Symptoms are a language which communicates a message and needs to be interpreted correctly in order to deal with the problem. Tearing pages can mean:
I am angry
I don’t like your education
I don’t like stuffing my room with toys
I don’t like you to tell me a story by reading from a book
Please help me

In stead the father prefers to stick to rules because as he understands the Baby will cope with law and rules better when it grows up. Ironically the very laws which are imposed by adults are abolished and declared wrong later. Changing the rules by saying it is/was right to tear pages means the Baby was right. The Baby was punished although according to the new rules now it did just the right thing. Adults are invited to understand a problem (if there is any) before reverting to law and punishment. We feel now it is time to punish the father for punishing the Baby ignorantly.

Finally the question is: why of all other objects does the Baby like tearing pages from books? The Baby stops tearing pages and starts tearing corners to avoid punishment. This means the Baby knows how to continue destroying books without the risk of being punished. The Baby has learnt (experience) how to show child maltreatment without the risk of getting grounded (German: Stubenarrest. This type of maltreatment (confinement to its room for such a long time: Stubenarrest) is nothing but imprisoning a child. Tearing books may also suggest that at least some of them (books /education /medical treatment) should be torn (abandoned) because they are simply wrong and misleading.

Wordsworth said: The child is the father of the man. Bad education and treatment in childhood is a serious issue. The Baby’s personality and identity is formed b at such an early and vital stage of human life by wrong education in spite of its cries of help and symptoms of mental disorder. Once a tree grows crooked it cannot be straightened easily

Babies usually need to develop their sensual and physical skills. By tearing the book the Baby can develop its finger skills. The book is theoretical, not practical, and useless for the Baby. Maybe they have already read useless books which the Baby now tears away. In his despair the father unfortunately goes from one extreme to the other. They (the Baby and the Father) represent different generations and different needs. In addition rules don’t help to develop the Baby’s imagination and thinking. On the contrary they stop them because rules are like machines or robots.

The Baby (additional remarks)
Rules are set by adults but ironically the very (stupid) rules are not only changed but reversed: In the beginning the baby was not allowed to tear pages but in the end the baby and the father not only tear pages but also smash windscreens. Education goes from one extreme to the other. In the same way children were brought up in the western world (Germany). Before the 60s parents were very strict (Zucht und Ordnung, Ordnung muß sein……) but after the 60s children’s education went to the other extreme: anti-authoritarian. Children were not only not afraid of their parents’ and teachers’ punishment but were disrespectful to a certain extent as well.. Education is unable to come up with the right dose of what should be allowed or not allowed. The limits are blurred. “The carrot and stick method” was criticized but no reasonable alternatives were suggested. This shows lack of understanding and insight. The baby must have been extremely confused when the father reversed the rules.
Different generations have different educations styles. We start from very conservative and strict education style and go to anti authoritarian. Parents have always been in a dilemma. In the beginning only fathers were present but now fathers are absent. Divorce rate has gone up and as a result there are more lone families (single parent families) than nuclear families. Right of custody is usually given to mothers and children grow up without fathers. Now fathers’ roles are restricted to financial support. This development has to lead to more step families and more conflicts.
It seems that highly educated parents of the generation of book readers don’t know how to educate and deal with children. The baby is right to tear the very books the parents believe would help them with their education. Some mothers and fathers say from experience that they only learn to educate children after the third or the fourth child. However, the standard family in the western world (Germany) is only one and a half children and maybe a dog or a cat. Finally the word “tear” is a word play : tear a book and shed tears.