I have been worried, though, by the idea that yin is on the left and yang is on the right and I was wondering about methods of combining them. I thought of O Sensei doing furitama, or "soul-shaking," where you hold the hands together at the hara and lightly bounce up and down. And I thought that's what he's doing there, balancing yin and yang in the two hands and spreading the energy through his body.
So I went looking for examples of furitama and found this article, which reads exactly right, but only if you understand the precise meanings of some gloss-over phrases:
Furitama is practiced standing with the legs shoulder-width apart. The hands are placed together with the left hand over the right. A small space is left between the hands. The hands are placed in front of the abdomen and shaken vigorously up and down. Inhale to the top of the head rising up naturally. Then exhale to the bottom of your feet as you continue shaking your hands up and down. The exercise if finished in silent and still meditative kishin.
This chinkon exercise was intended to gather the spirits of the divine into ones center (added emphasis DO)
... calming the spirit... vibrating the soul. It's an effective way to gather your thoughts, center your mind and focus your intention.
END OF QUOTE
This is the kind of statement that is easy for the mind to skip right off of and simply provide a meaning based on the image of "the spirits of the divine." And that, clearly is where so many people have gone tangent to the actual art.
Not only does it not say which spirits, given as plural. It doesn't say how many spirits. And since we know that Japan has kami all over the place, we might think it means "all the gods of Japan," as I think it's actually phrased in the story of Morihei at the well after surviving the Naval officer's sword attacks. There was a purple cloud and all the gods of Japan entered his body...I think.
But if we look at furitama as gathering the specific "spirits" of in and yo into our body and vibrating them along with the body and breath, then it really means aligning the body with the "principles" of in and yo to harmonize and energize it.
So suddenly that exercise looks like it has a lot more meaning than I ever imagined and I'm adding it to my research right away.
IMO, it sounds like you're going in a different direction. If the floating bridge of heaven is the turning of fire and water together, think of in/yo. Think of contradictory forces moving around each other. You get something like the yin/yang symbol. Standing on the bridge is to be in the middle of all that.
No disrespect, but I personally wouldn't go by the article's explanations. If you're thinking that you're shaking your hands up and down, you're not doing what Ueshiba did. Again, all IMO. But, looking at millions of people who have trained aikido for 10-40 years who think that it's shaking their hands up and down to calm the spirit ... well, how far has it gotten any of them to Ueshiba's level?
So, it is something completely different. If you read some of Ueshiba's translated works (mostly by Chris), you find talk about how in was on one side while yo was on the other. Correlate that to some of the Chinese works and you find it very similar, sometimes identical. So, when you read about that "purple cloud", I would research some of the Chinese texts because there is mention of a purple light as a stage in internal training. Ueshiba was merely echoing many known martial things, just in his own spiritual way.
Ueshiba was training in/yo when he did all those exercises. Which explains why he gave the answer to Kono. Find inyoho. Train IP/aiki. Change the body. Then, when you move, techniques will be born.