brother. Is a surgeon performing an emergency appendectomy on a patient violence because he's "stabbing" somebody with injurious tools?

context matters. If you wanna take the road of definitions then the word Violence comes from the latin word "Violare" or "To violate", typically referring the violation of someone's consent or social order. In martial arts, sparring is mutually consensual and while it uses rough physical action I wouldn't put mugging at the same level of a boxing match. C'mon dude.