Yes, he was, Dan. And a fine person with a great heart.
And he did tell me once that aiki is "the ura of kiai" but I thought it meant the ura of the attacker's kiai (to produce a technique adhering to the "reverse" of the attack).
However, my experience with you and others left me stumped until I thought of it as the reverse of my own kiai. That was another ura in itself.
But please: what do you think of that conception, as one of the few who can demonstrate powerful aiki and affect the opponent unquestionably?
I can think of many concepts that would fit this type of comment in Budo. Therefore I would hesitate to address your teachers meaning. However, I can think of several working definitions for the ura of kiai; chief among them would be in yo ho; to be at one in harmony in all movement inside you. Or aiki in yo ho as breath training (which he would have been familair with) would also fit. Nice power exercise. But power will not due and breath-power is just a piece of the puzzle?
In/yo or yin/yang is a concept many artists have heard of. They like to think of this concept in what they do. I struggle to find it in their movement. trying to find it in anyone in the Japanese arts to any serious degree may prove to be a chore. Instead people like to divide their mental state; they do this as a yin movement of feel, that see that power display and they think of it as a yang movement. This is not in yo ho. To be at one, we have to possess both at once. Is that what you’re teacher was getting at or pointing to, I dunno. If he knew, why he didn’t explain and show how, where, why and in what manner you would need to train to create contrasting energy and then contrasting dynamic movement to support all action is disappointing I’m sure.
In any event to be ideal, all energy is matched and supported in contradiction, it is in/yo ho. Aiki is in/ yo ho and it can be taught. It is easy to show in sparring where and how incoming force gets neutralized, redirected and they get owned without much thought. When the energy inside is matched by the expression of energy in physical motion outside- there is a marked tendency for them to always have to react and re-adjust to you, while you are just moving. This creates a time lag or reaction displacement in them, where they feel as if they are always behind you or after you, giving you a natural edge in motion to exert your will by fitting in to the gaps that keep revealing themselves. You can couple that with other physical effects (external movement manifestations) where many time one distinct movement from them offers you two or three openings. I call them two for ones (someone with aiki power can usually hit two or three times in an opening-where the normal person can't. The reason is the power is inherent and latent and I don't need to wind up. The power just changes from one spiral to the other and is a constant current in the body. This gets very complicated when you start to see just how capable opposing spirals are all along a path. Someone trying to throw you encounters spiraling descending energy in a leg that looks like it isn't moving, and their force get multiplied into a kick or punch the likes of which they cannot fathom where it cam from, all while you are perfectly free to keep moving right through them and force them to react to your natural movement . Once the body becomes aiki (a balance of matched energy in stillness and in motion) it expresses aiki on contact. So with "my" idea of the ura of kiai (in yo ho) the body tends to take care of itself while their strength and intent is dissolved and or manipulated on contact and once again…they're late in reacting…too late.
Just a quick note on your comment about being immovable. Everything we’ve discussed is hyper-mobile and immovable at the same time. The key to all, is change of energy; theirs and yours, not that "holding ground" absorbing stuff. That's how you get caught; joint locks, throws, what have you. Good martial arts guys (like softer aiki-jujutsu guys) will lock you with multiple directed vector movements and cumulative bone locking, and throw you with a certain type of “contact understanding” (that I won't go into here). There are methods of fighting that. "Store and release" methods, and “breath-power” methods, among other things, are just not going to begin to address that and will be read, undone, or gone through. Power is not the answer. It takes a deeper understanding of how and where to train the body to cancel that stuff out, make change, and put it back in them.
The method can get complex and detailed and they are NOT all the same. You remember some of the external examples I showed of spiral energy and how it looks and acts exactly like so many familiar waza? Its one of the reasons people can mimic but have no real understanding. Once there is a real balances power, technique is meaningless. You've seen a direct jab that does nothing and is gone right through and the guy is hit twice for his trouble? Think of that now with something as obvious as a shomen/yokomen and how much easier that is to deal with? Think of sword, think of naginata, think of twin sticks. You literally move through them and hit them, or displace them and motivate capture and control them, or throw them. The reason is that spiral energy inside matches spiral energy expressed outside and this creates aiki on contact; an unending method of disruption based on certain key requirements; some of which you to build in your body and others of which have to be burned in to be tactile. The way you are training the energy to move inside you, should match the way the energy is expressed outside you, in movement. Without that you have…well…a whole bunch of martial artists moving like athletes, and some physics and engineering junkies creating models and graphics to express their “understanding”- who are unable to do anything meaningful with their "understanding."
So the ura or kiai is up for grabs. I remain convinced from ever increasing exposure that my kiai is not like most peoples kiai, so the ura of that will be different than the norm, how that plays into what Mr. Mochizuki meant is not defined. He was after all a Japanese teacher- so why bother “defining” anything.
I hope that helped.