I see a lot of reviews that point to the physical abuse this book advocates, which is true, horrific, and important to highlight. However, I noticed no one was really talking about the emotional abuse this book instructs parents to inflict on their children. I was raised according to this book, with one caveat: my parents couldn't break my will using physical punishment, and they couldn't stomach escalating physical punishment to the level of abuse as the book recommends, so they used emotional punishment (rising to the level of what I'd consider emotional neglect and abuse) instead.
It was better than being beaten, I guess, but it wasn't good. The effect was still harmful, because the root of what this book prescribes is the stamping out of any genuine emotional expression in children. According to this book, a child's perfectly normal needs-- to be held, to feel safe, to explore and be curious, etc.-- are sinful, selfish, and should be stamped out in favor of complete submission and unquestioning obedience.
Even though my parents never stooped to the level of physical abuse, I grew up with a deep, pervasive sense that my own emotions were manipulative, selfish, and wrong. I learned to avoid asking for what I needed and developed serious attachment issues that still affect my relationships to this day.
To sum up, it isn't just the physical abuse that makes this book problematic. It's the underlying philosophy-- the idea that children are inherently sinful, and that their normal, natural modes of self-expression are something to be punished or ignored. It's harmful, period. If you are a parent looking for something to help your child grow up with self-control, think about whether you want your child to have *so* much self-control that he/she no longer has any instinct to protect him/herself, or any sense that he/she matters or deserves to be loved and comforted by others. If you want your child to feel eternally ashamed of having normal human emotions... use this book.