Raising a child can be such a puzzle...
I agree with mickey here that it is the parent's duty to teach their child about moral and responsibilities. They experience social life much more at school, but the parents have to be the first ones guiding and "framing" the kid. Both parents and school work to the child's social developpement, but in different/complementary aspects and ways.
As for how to apply this as a parent and settle its authority, I think that explainations and dialogue are the best mean. The way I work personally with kids is to go with reason: I have solid points when I forbid something; it's longer because that opens the door to debate with the child and you have to explain everything, but it works better usually.
Unfortunately there are some tougher kids, and more rebellious teenagers, with who it doesn't always work (often a question of lack of goodwill, of desire to challenge); those can sometimes push us to our limits... I think it is different for each case, but sometimes, in some situations, childs have to be shaken when things get out of reason. It is not usual, but it happens; and one of the ways possible is to use force. I am agaisnt harming children, but I undrestand that a parent may come to smack its kid's behind or fingers, or grab the child strongly by the arm.
I wonder if some decades ago there were such questionning and debates about the way to raise & discipline his kids?