From the time a toddler first begins exploring the world, parents are faced with the issue of what will not be allowed. Quite simply, we cannot allow them to do things that might cause damage to themselves, to others, or to property. And they spank or slap a lot when such words do not work. The problem is not a disobedient child, the problem is the parents. There is a better way.
Actions speak louder than words and actions can be kind AND firm.
The real issue is how to teach the child what actions are acceptable and which are not. Parents are bigger, they simply don't allow the toddler to do unacceptable things. The toddler WILL scream and howl in protest, but that is what a child does. A child doesn't have to react like an adult. The parents do.