Re: The two body/mind concepts of Japanese Martial Arts.
Graham doesn't need any help but I would just like to point out that he started the thread - he gets to decide what he's talking about. Trying to move the discussion to internal stuff and to someone who doesn't even do aikido was disingenuous and just a distraction. This is in the spiritual forum - if you want to talk about internal stuff please do it in the non-aikido martial traditions forum.
Graham didn't say anything revolutionary - koshi is a normal concept in martial arts. Maybe there are some differences in definition but it's a pity that the interesting suggestion he made that you connect to earth with koshi and heaven with hara is getting lost.