MtheGM commented, inter alia:

all well-thinking people can see that punishment is generally a vain & disagreeable procedure which will solve little or nothing; but still no-one has ever managed to dispense with it or come up with a better idea.

That's far, far too broad a statement, even though watered down as it is with "generally" and "little or nothing".

The word and concept of "punishment" is being confused (in most of the posts in this thread), with "penal punishment", to which the quote above might be said to apply.

The correction, guidance, discipline (what have you) of children and teenagers, just for example, by the aid of such punishments as time-outs, being sent to bed early, groundings, time-limited deprivation of favorite toys or clothing,temporary or even permanent banishment of certain friends, withdrawal of driving privileges or the use of the family car, are all punishments that may be appropriate and effective.   

Vain & disagreeable procedure. Disagreeable, quite possibly. Many, many necessary actions in this life are disagreeable, but that's not a meaningful argument. And "vain"? Not "all well-thinking people" can see anything of the sort. Unless you define "well-thinking" as agreeing with your judgment.

I will agree with you, however, that no-one has ever managed to dispense with it or come up with a better idea.

Dave Oesterreich