The only thing physical discipline (the rod) reinforces is more violence. If they're taught that their negative actions have violent consequences, it causes them to look at the world differently. They don't learn from their actions, they only live in fear. It's a ridiculous way to raise a child - and in what civilized world do we strike children anyway? It's the twenty-first century.
Corporal punishment teaches a child to be afraid of their parents. It doesn't teach them anything, except that they need to avoid getting hurt. It's not great for a child's emotional, mental, or physical well being. It also doesn't work that well. Almost all parenting experts recommend consistent, respectful discipline as the best way to teach a child and mold them into well adjusted, responsible adults.