| It's not just|
a good idea
Corporal punishment is the use of violence, specifically pain, as a form of punishment. Usually this involves striking an offender in some way.
Corporal punishment has been widely used throughout history by many governments, as well as schools, armies, navies, employers and parents. It remains common to many societies, although the laws restricting it differ widely.
Corporal punishment is controversial because in a free, just and modern society, dealing with people through violence means does not square with the notion of inviolable human rights. There is also considerable debate over its effectiveness, and the long-term physical and psychological effects it can have, especially on children.
 Child disciplinary issues
Notwithstanding the expected exception, most Western democracies have outlawed corporal punishment in schools or by the courts. There remains controversy as to whether or not parents may strike their children for disciplinary purposes. In the UK, a survey suggested that a majority of parents supported the right to smack their children, although a minority understood the legal situation.
Some parents claimed that smacking a child provided a shock to them that remedied bad behaviour, but this must be balanced with the possible problem that a child grows up to believe that violence is a way to solve disputes. There's no clear consensus on this, and there is obviously a difference between an occasional light smack and beating a child on a regular basis. Proponents have also used the argument that they were hit as a child, yet "turned out fine", a rather fallacious argument. The context in which the punishment takes place is also important, since the parent's punishment may be more influenced by their own emotion state than a rational determination of the action necessary to correct the behaviour of a child. It's a bit like allowing a judge to preside over a court case (and act as the jury) in which the defendant is on trial for punching the judge shortly before the trial began. It's difficult to guarantee an impartial appraisal of the case.