You can defend yourself without inflicting pain - by avoiding the confrontation in the first place. If things have gotten to the point of an unavoidable physical confrontation with someone who is genuinely trying to do you harm, then it's not very likely you are going to be able to subdue your attacker without inflicting pain. You're doing well if your joint lock restraints manage to work with only pain inflicted rather than having to actually break a limb.Karate is about self defense, not fighting. I believe there is a difference. If you are fighting, you are looking to inflict pain. If I can defend myself without inflicting pain, that would be preferable. If I can defend myself by using a lockflow technique and restraining someone until police arrive, I would prefer that to breaking the opponent's arms, if possible, if my goal is self defense. If I am in a real fight, I would try to break his arm. I may have to break his arm just to defend myself, but I would avoid it if possible.