"The ultimate aim of the art of karate lies not in victory or defeat, but in the perfection of the character of its participants." -- Master Funakoshi Gichin
We study a fighting art. And to learn it, we have to practice fighting skills with each other. That ranges from holding training bags for each other through drills with prearranged attacks to free sparring. So its very important that we treat each other carefully. As my sensei Jun Shihan Kate Stewart once put it, if you keep breaking your training partners you end up with no one left to play with.
And that idea of treating each other carefully isn't just about not physically hurting each other. We have to take care of each other's hearts and spirits. The traditions of budo give us a way to do this, through the rules of dojo etiquette. Like all such sets of rules, there are some things about them that are arbitrary or that seem strange when we first encounter them and don't understand the context in which they arose. But these rules give us a common framework, a common language of action.
It's also vital that we show that we are trustworthy of learning this art. Karate is not dancing or playing guitar or painting. If you're a bad person who learns how to paint, you can't do a lot of damage with that. But if you're a bad person who learns karate, you use it beat people up. If we don't show that we have the maturity and judgment to use what we learn wisely, then why should our teachers give us skills that make us more dangerous? Proper and respectful behavior in the dojo is the main way that we can show that we are -- or at least might be -- responsible enough to be taught.
It also helps keep our egos in check. As we learn these skills, we can start to get proud of them, to think we're really hot stuff. "Look at what I can do! Check out this kick! I'm the best!" It's one thing to take joy in doing something well, but if we go from that to puffing up our self-importance then karate doesn't become an art of self-development, it becomes a means of self-aggrandizement. When our ego gets too big, it gets in the way.
And this isn't just for students. It's for instructors too. Please notice that at the start and end of every class, when you bow to me, I bow back to you. Even though I've been doing this for almost thirty years, I'm supposed to bow to brand new students. Even Kaicho Tadashi Nakamura, the founder of Seido Karate and a living legend in the martial arts world, bows back when students bow to him. So please follow this example.
Take time to acknowledge and respect each other. That's really all that the rules of dojo etiquette say.