Peter A Goldsbury
One problem is that Ueshiba explains the symbols in terms of kotodama theory. He uses the the circle, square and triangle, but also three more: cross in a circle in a square; circle bisected four times; same bisected circle in a square. This is all in the (as yet untranslated) Takemusu Aiki volume. Clearly kotodama theory would be the place to look.
Thanks for the reply,
Interesting, I'll have to look into getting a Japanese copy of Takemusu Aiki then. While some of the details differ, we similarly have various combinations of the symbols used together and separately. Square in a circle, triangle in a circle, two triangles merged to form a 6 pointed star inside a circle, circle bisected by the straight line, circle within a circle, cross, etc. I get the impression that Ueshiba wasn't breaking new ground so much as playing with and putting his own spin on possibly well established themes.
As an aside, I've only just recently started reading aiki related things in Japanese, but in English we often hear of the idea of "not clashing" and such, but was there any particular phrase that Ueshiba was fond of using to express this idea? I ask because over the years I've found an awful lot of "common ground" philosophically between the ryu I practice and aikido and one of the major tenants of our ryu is something known as 不当之矩 which was one of the first things that really grabbed my attention in the "well this sure sounds familiar" sense several years ago.