Permissiveness involves not trying to control the behavior at all or not providing consistent consequences for behavior. Remember the principle I discussed in the chapter on responsibility. To teach a child responsibility, give him all the choices he is able to make and allow him to have the complete consequences of those choices. I think you could adapt the idea behind that principle to the permissiveness question. Some of your child's requests may be easy to decide on, some may take some thought.
Authoritarianism can be overdone.
He is likely to expect the worst, having learned by experience that everything is likely to have bad consequences. When the parent is successful at controlling with authoritarianism the child is likely to grow up cowed and fearful. When the parent is unsuccessful, the child is likely to be rebellious. Neither of these is a desirable outcome. Authoritarianism can also lead to attempts of the parents to control directly the behavior of the child through force or physical control of the child.