Even a jury of non-martial artists would be hard pressed to find anything other than "guilty" when the defendant says: "He was walking toward me in what I perceived as a threatening manner, using harsh language, so I launched myself at him first". My common sense question as a juror might well be "Could you have gotten away in the first place, and why did you throw the first punch or launch yourself in order to "defend" yourself?
My teacher Stephen Hwa, Ph.D. tells me that Classical Tai Chi is a pure "defensive martial art". In the video you see him explaining and demonstrating the difference between "offensive" and "defensive" with the catalyst explained as "jumping off" or momentum force. So the question is if you launch yourself in any fashion toward the opponent to "defend" yourself, how is that a "defensive" tactic?
I have taught quite a number of students that do external or what are called hard style martial arts. Certainly, one can be attacked by hostile people, hostile animals, etc. But the question for me is at what cost do you defend yourself? I agree with Master Hwa that "...in a fight, anything goes..." But is your integrity, common sense, and training guiding you in "anything goes" defensively or offensively toward the attacker? From time to time, one of my students will remind me that that there are martial arts better, faster, stronger and quicker to learn that Tai Chi. So in that reasoning, could one learn to do several different martial arts, learning several times faster than Tai Chi and be several times better? Many indeed, very pretty, even flashy but are these several arts "offensive" or "defensive" because if they have a hint of offense, then don't they cross the line?
In the 1990's I was contacted by a martial artist named John C. John had seen me doing Wu's style sword form and asked for lessons. I told him I would teach him the sword if he learned the Wu's Square Form first. Note: This is not Classical Tai Chi's square form. John reminded me periodically that he had learned 7 different martial arts faster and appeared in an Inside Kung Fu article. He said that he learned those faster than he would ever learn Tai Chi and hence never did learn the sword.
John, however, did not use internal discipline where one part in the core moves and one part does not move in any of the 7 arts, by the "jumping off" definition his arts were "offensive". My student Barry who did Karate and taught defensive tactics as a parole officer did not use internal energy. Barry told me that he has learned several martial arts but that learning internal discipline has been the most challenging, by the "jumping off" definition his arts were "offensive" Another of my students Anh has done Wing Chun for a long time but says learning internal discipline is more challenging and sophisticated.
In conclusion Master Hwa makes a great point that there is a big difference in the use of force "offensively" as compared to "defensively". In another segment of the video he also states that Classical Tai Chi because of its dependence on a non-moving part of the body is a purely defensive art. If one is not moving that one part of the torso in other words, then how can you launch yourself toward the opponent while maintaining that non-moving part albeit in full momentum?