I was discussing pillar theory recently because Jason DeLucia has some video clips up on aikidog.com labelled "5 Pillars" but I couldn't figure out exactly how they corresponded to the pillars I'd seen in various books. He said different teachers pick different pillars (number and content), so that got me scurrying for my references. As usual, I head for books when I'm trying to assimilate something on an intellectual level.
Pretty much all the big names in aikido have their own list of pillars or principles. The ones who say there are 50 or 100 or 150 basic techniques aren't all that helpful to me, it's the ones who boil it down to basic principles that I like.
Katsuyuki Kondo has a very nice list of seven Daito-Ryu Aikijujutsu kihon (basic principles, or pillars) for comparison: rei, metsuke, maai, kokyu, kuzushi, zanshin and
Gozo Shioda lists six: The Power of the Center Line, Focused Power, Breath Power, Ki, Irimi, Kaiten.
Kisshomaru Ueshiba lists basic principles: Posture, Assuming Ma-ai, Move in the Center, The Flow of Ki, Sen (anticipation), The Use of Power
Then he lists basic techniques: Ki no henka, Kyoku no Tenkan Ho, Ukemi, Irimi, Kokyu
Kisshomaru Ueshiba and Moriteru Ueshiba say there are 50 fundamental and basic techniques and say that the basic techniques build on the fundamentals. As fundamentals, first they say "Breath power and ki are the source of Aikido strength" and then they list these fundamentals: Kamae; Ma-ai and Me-tsuke; Rei, Zaho, Shikko; Unsoku; Sabaki (Irimi, Tenkan, Tenshin, Tenkai); Ukemi; Te-Gatana; wrist warmup exercises; back stretch; Tai No Tenkan (Shiho-giri).
Westbrook & Ratti in AIKIDO AND THE DYNAMIC SPHERE list four principles, quite distinct from discussion of technique: centralization, extension, leading control, sphericity.
And this is Bruce Klickstein's list from LIVING AIKIDO, the book endorsed by Morihiro Saito: Ikkyo, Shihonage, Koshinage, Kokyunage, Iriminage.
I'm going to have to chew on this for a while, but am hoping you folks will come up with some good food for thought comparing/contrasting these other people's "pillars."
Jason posted something about pillar theory in a discussion on Martial Arts Planet a week or so ago:http://www.martialartsplanet.com/forums/showthread.php?t=35675&page=13&pp=15
He's going to love this thread (and probably the Muteiko one, too) but he doesn't have computer access for a few days.