> Along a similar line, I’ve heard it say that if you consider yourself a peaceful person but are not actually capable of great violence, then are you actually peaceful or simply harmless?

Why not both peaceful and harmless (for the moment)? This is a function of time. I don't think it's possible to make that statement without supplying the time parameter.

Also, I don't think peaceful people are not capable of great violence. It's about choice. I'm capable of violence, but I choose to not use that capability.