Why is the second volume of Lu Ban's book so harmful? Why is the scientific explanation unclear?

This book is China's feudal culture, which is immortal and harmful to people. If you call books rude, you will avoid history, which may not make people's hearts disappear, so it is harmful.

It is said that learning Lu Ban Shu needs "one subject", and you have to choose whether you are lonely, lonely, solitary or disabled ... Therefore, Lu Ban Shu is a wonderful book in ancient China. It is said that it was written by Saint Lu Ban. The first volume is a magic trick, and the second volume is a solution and some medical spells. However, except for medical spells, there is no clear cultivation method for other spells, only spells and symbols.

Extended data:

According to some unofficial history records, there is a legend in this book that Lu Ban's wife was pregnant, but it happened that Lu Ban was going to work in other places at that time. Two people will inevitably miss each other. So Lu Ban thought of a way. He made a wooden kite that his wife could come to him and taught her how to operate it by herself.

After that, his wife can often see him. But I don't know if it is because of studying Lu Ban's books that his brothers' family life is also very unhappy. Most of the children born in his brother's family will die young, and his family will become more and more unhappy.