I've been asked this quite a bit recently and it's one of those questions that pop up from time to time so figured it was about time to try and answer it the best I can. I will admit that even after many years of teaching people and training dogs that I still get a little stumped at how to make sure the answer I give will be understood properly. So here goes......
As I understand it I think people think that a dog needs to be taught "right" from "wrong", and that when the dog does something considered "wrong" then the only way to ensure that "wrong" behaviour doesn't happen again, is to discipline the dog.
Discipline meaning to punish rather than discipline meaning having exceptional self-control.
Okay so if that is what I understand it to be inferred then my answer is simple:
Teach, train for, show, set your dog up to do what you are happy for it to do.
Why would you put your dog in a position to fail?
In order for a dog to live successfully with us in our world we need to help them learn to live happily within our social needs. But we need to always remember that a dog is a different species to us humans and because of this the dog will also have social and behaviour needs that must also be met in order to flourish; which in turn is what generally pleases us.
So rather than "disciplining" or "punishing" a dog for doing something that doesn't please us perhaps we (supposedly being the more intelligent species) need to work out how to teach, train for, show, set our dogs up to be successful and then there is never a need to discipline or punish.
Dogs can "discipline" each other; they do it instantly and quickly but then they "get over it". Often their "discipline" is no more than a look or a facial movement; think of when you encounter friends or family that are not in the happiest of places - the saying "could cut the air with a knife" is one that most of us will sense without the need for physical or verbal interactions. Dogs are sensitive souls who only wish to please; the need for humans to "discipline" their dogs often comes from said human not having thought about consequence to their own actions and therefore failing to set their dog up to succeed.