Since the "Eight Powers of the Kototama" has been brought up, let me just throw this out there. The most prevalent reference to "Eight Powers' as it relates to Kototama can be found in the Dobun - here is a link to it on the aikidogaq site:
This appears to be just another translated interpretation via a filtered perspective based on one's opinion of what Ueshiba was saying and writing. In order to find a more objective viewpoint of the Kototama, I went to Masahilo Nakazono's book Inochi; which goes into the Kototama in much detail. In the book there is no reference to ‘Eight Powers' as explained in the Dobun, but there is reference to the four mother sounds of U, A, O, E and the eight father sounds/rhythms of T,K,M,H,L,N,Y,S, which when combined create the child sounds.
Interesting enough though, there is reference in the Dobun and Inochi that support Dan's statement of:
＜念＞にもとづき『気の妙用』をはかるには、まず五体の左は武の基礎、右は宇宙の受ける気結びの現われる土台であると心得よ。この左・右の気結びがおのずから 成就すれば、 あとの動きは自由自在となる。
"In order to achieve the mysterious workings of ki based upon intent, first realize the appearance of the foundation that is the ki connection (ki musubi) between the left side of the physical body grounded in the martial and the right that receives the universe. If you can achieve this connection between the left and the right then you will be able to move with complete freedom."
In Inochi, Nakazona states that ‘U' is the chaotic beginning and ‘A' is the light of life; ‘WA' is phenomena lit up by the light of ‘A' , and each dimension is an independent manifestation. He also goes on to explain that ‘A' represents the a priori and ‘WA' the posteriori human capacity, which is connected via the ‘I-WI' life force dimension, which is KI. In looking at Dan's statement above, you see that the point being made is that one part of the body is connected to "A" and the other ‘WA' - or the spiritual and physical with the connection enabled by Ki - or the in-yo of the human existence.