VC wanted more on the value and the cost of a conscience. It's not some deep or profound thing, if you think about it... but many people go their whole lives without being exposed. Some things suck. There are many things that are cool to think about that suck to do.
When you apply force to a human being you should only do it when it is the right thing to do, when the costs of not applying force outweigh the cost of applying force. If you pull the trigger (and you don't miss or...) no matter the circumstances, you will have destroyed a unique thing. Something more unique and of greater artistry than a Rembrandt or the only copy of a Mozart fugue. Would you destroy "Starry Night" to save your daughter? I would. But I would feel bad about it.
The cost of a conscience is two-fold. The fear of bad feelings can make people hesitate or not act at all. Don't get me wrong: fear of other bad stuff can also keep people passive and make them victims- but fear of your own conscience is an interesting thing because it is both very powerful in (some people) and completely imaginary. The other cost is that people can beat themselves up emotionally over things that are objectively good decisions. That's just the way it is. No matter how logical and necessary the action was, you can expect to wake up in the middle of the night for a while (sometimes for the rest of your life) wondering if there was another way.
And the cost is the value. The feeling bad and the expectation of feeling bad is what keeps us from using violence as a convenience. Those that don't have this do horrendous things.
Thus, as near as I can remember in Toby's words, comforting a girl who defended herself: "That you feel bad doesn't mean you did a bad thing, it just means that you are a good person."
There were a lot of good comments on the post on teaching, but Robert made one about context and permission and working in the jail. I'm going to deliberately misunderstand it in a useful way, a way that ties into conscience:
One of the keys to personal 'permission' was a by-product of working as a corrections officer but is not dependent on it- I knew (and had to know) force law inside-out, upside-down and backwards. Knew it so well that I could compare it with my feelings and internal ethics and work out the issues well in advance. For the most part, I found that when an instructor said something that made my eyes twitch e.g. "You are authorized to use one level of force higher than the threat," my instincts were usually spot on.
There are rules. There are social-monkey rules to conflict that we have learned from birth. And there are legal rules that we are beholden to whether we want them or not. When one person says "I'd rather be tried by twelve than carried by six," does he also say "I'd rather spend seven years in a state prison than take a beating." ? Without a thorough knowledge of force law and probably a good knowledge of real conflict- at least enough to recognize when you are monkey-dancing and not defending yourself- you might find some pretty weird thoughts popping up in a conflict.
You can choose to believe that you are immune and if you have one or two encounters that only last a second, you might not have felt it, but get a copy of "Deadly Force Encounters" and take it for a read. Even trained officers in life-or-death firefights found themselves worrying about lawsuits and IA investigations.
So part of the context, Robert, and in my opinion more powerful than the uniform or the duty to act, was a really thorough knowledge of the rules. There is no reason why a martial arts student can't know this as thoroughly as I did. For that matter, there really isn't a good excuse for anyone who bills himself as a self-defense instructor not knowing this stuff.