Here's an excerpt (with some relevant links added):
I don't think punishment--as in Child does XYZ Bad Behavior and then I as the parent must then do something to the child in order to make them either understand that the behavior was bad or feel bad about doing it, such as sit in Time-Out or be grounded or hit or screamed at or shamed--is necessary.
I want to guide my children toward full rationality and the virtues I prize, rather than control them into it. I look at punishment as a way to try to control the child's behavior rather than teach the child what's expected. Obedience--the end result of being well-controlled--is not a virtue. I don't want my kids to know how to obey me. I want them to be independent, productive, honest, be just and moral, have self-control and integrity. And this entails rationality, which cannot be present without volition, choice.
Kids need practice at making good decisions. (Actually, many adults I know could use a refresher course, too.) They're going to make good ones and bad ones. And they're not fully rational either [insert obvious joke about adults here]. But I think that PD respects a child's nascent rationality, and in fact, bolsters it--by allowing them to practice and make mistakes without punishment.
When Brendan makes a mistake, I don't punish him by making him sit in Time-Out. Once, I accidentally dropped his computer and it broke. I didn't go to the Naughty Chair--I got the computer fixed. PD is more in line with how adults treat each other, while making allowances for the immature brains and less experience that children have.
Since that post, I (along with Kelly) took a couple of classes about teaching these techniques to parents and am currently a Positive Discipline Trainer Candidate. The fun thing about teaching and taking these classes is that it helps concretize some of the ideas. Sometimes it's a bit of a stretch to imagine what a home with no punishments or reward systems might look like, how a parent handles discipline situations. The classes are designed to demonstrate and even give the participants some practice in using the ideas. I'm definitely looking forward to teaching more classes in the future.
If you have any questions about non-punitive discipline/Positive Discipline, I'd love to hear them!