Re: Masakatsu Agatsu
This is an interesting topic, but I think I need to add something so that my position is clear:
1) Jiriki and Tarki are Buddhist terms that stem from the same underpinning cosmology that informs ancient and more modern ideas about Ki - unification of opposites (heaven earth man)
2) That cosmology informs Japanese Shinto, Buddhist philosophy and practice, and many of the arts - including the martial arts
3) That same cosmology gave rise to the cultivation of Jiriki for martial as well as spiritual purposes - the distinction that we draw is a modern day one
4) There is no necessary correlation between mind body coordination (unification of opposites) and spiritual development. Spiritual progress is not guaranteed and having a spiritual predisposition does not, by the same token, guarantee martial efficacy
5) Training can work wonders for anyone prepared to put in the time and effort
In the quote that came from me I was talking about Ki in terms of power, personal and impersonal - individual Ki and universal Ki (heaven earth man) as equivalent to Tariki and Jiriki (not the same as). Taoism is full of cosmological correspondence, but it all hinges on the 'great root' or 'pole', yin and yang.
All I am saying really is that Ki has a micro/macro aspect, and when talking about Ki it is impossible to avoid yin and yang if you want to discuss it in any meaningful way - the unity of opposites. Ki in itself does not mean very much without reference to yin and yang.
As a concept Ki is Taoist in origin, and borrowed subsequently by the Japanese. Through time what was an essentially Chinese cosmological concept became integrated through the merger of Taoism and Buddhism, resulting in Zen Buddhism (Ch'an) in Japan. As an ideology Zen was adopted by the Samurai elite , who found martial applications for the cultivation of Jiriki and paired it down (secularised) for military purposes. Later, in more peaceful times, this process was reversed and Jiriki was reinvested with a more spiritual significance, but only after various factions (secular and sectarian) had stopped slaughtering each other (See for example The Life Giving Sword, by Yagyu Munenori).
An interesting question is which came first: the dissemination and cultivation of Jiriki by monastic orders for personal liberation, or its cultivation for martial purposes? I am more inclined towards the former, but it is also true that martial skills were developed by monastic orders for their own protection and preservation of land and property: "the one can be used for the many."
Another interesting question, and one that I don't know the answer to - but maybe somebody here does - is: At what point, did Jiriki become Ki? In Munenori's work he (or the translator) used the term Ki, but, as the translator points out in his notes, it had a multi-faceted meaning and care needs to be taken when interpreting or ascribing meaning.
It would be interesting to find out when the term Ki came into common usage in the Budo world, apart from Morihei Ueshiba's use of the term and Tohei's Sensei's re-branding of Aikido. Did Sokaku Takeda make much use of the term? I don't know, but I would be surprised if he did. But this does not have much to do directly with Mathew's post.
Religious and spiritual perspectives, interesting though they may be, tend to complicate and confuse most issues. Practice on the other hand, is designed to keep things simple. I think that for me, this is the message of Masakatsu Agatsu.
While there have been various attempts by some at different times in history to elevate Ki to a more spiritual level, my own feeling is that this is a form of self-conscious spirituality - a form of vanity. I've been guilty of it myself, but we learn through our mistakes as we grow up.
After all, common sense tells us, there are many Chinese - good communists and atheists all - whose ability to use Chi is exemplary. One does not have to be self-consciously spiritual to use Ki, just have a body and a mind that is susceptible to training.