On physically disciplining children

Disclaimer: What I'm about to say doesn't mean beating your kids senseless is ok, it is possible physically discipline children by restricting freedom, meaning: hold them until they calm down etc. Use common sense, you want to restrict, punish and teach the kid for his/her own good, because you care about them. And they will have to live in a society with other people on their own some day, and that's what you are preparing your child for.

Words don't mean anything to a child, unless you bind them to physical reality (which is the place we operate in). Every single life form understands pain (because they avoid their own destruction, which is what the feeling of pain signals: "this is negatively affecting your existence"), and that's how you teach the meaning of "No": through pain, through loss, through adversity; this is basic respondent conditioning (Pavlovian).

You have to bind "No" to negative real world consequences, then you build on that so the child learns to navigate the world so well that he/she avoids the "No"s as well, while simultaneously getting to his/her own goal.