I don't think of spanking as a way to inflict pain on your child. Generally a light tap/spank will do. It's a way to re-focus them.
Originally Posted by babywavy
Whether it hurts or not, it's still humiliating. I'd much rather find non-physical methods to re-focus ds.

You're basically reiterating the fact that mommy and daddy are the parents, and they have the right to do things that children can't. We also use sharp objects, when we tell our kids to not play w/ them, and we drink alcohol when we teach kids to not drink it. It's not hypocritical, it shows the control, and certain amount of power (for lack of a better word) that parents have, which is important in teaching kids to respect you.
The above ideas can be conveyed through words and actions. I just can't find a rational way to justify hitting a child "because I'm the parent." Spanking a child isn't positive modeling. They say children live what they learn. They learn from our words and our actions.