If parents disagree on how to educate their children …

When parents disagree on how to educate their children, the harm is far greater than having both parents go the wrong way in raising a child.
If you can’t reach an agreement with your spouse and your spouse doesn’t reach your spouse, you should do the wrong thing for your spouse instead of going the wrong way.

The harm a child sees from the misbehavior of a parent is far less than the disagreement between parents. It is as if the child’s parents were locked in two cars and each had their own way.