Re: Defining Kokyu
Mike, those are good questions. The idea of breath power itself must contain and rely upon other aikido principles. Breath has an inherent timing element, and therefore is almost synonymous with timing. In addition, humans cannot do many things very well while breathing in, so it is important to control your own breathing patterns in order to facilitate action and control tempo. As any athlete will remark, breathing speed and control is directly connected to relaxation, not just during meditation, but at all times. Someone who can breathe evenly during a tense situation can think more clearly, react more precisely, and can keep his body from becoming stiff.
Of course breath has a deeply spiritual element as well. Respiration is synonymous with life, and represents the ebb and flow of all things in the universe. Sound (especially vowel sound) is connected to divinity in all cultures, from the tetragrammaton (YHWH = IAUE, the name of the Hebrew god) to the kotodama of Aikido itself. Sound is only possible through breath, and sound can only be made during half of the breath cycle, which demonstrates the equal and opposite power of silence. Osensei believed that different movements were a physical expression of different holy sounds (vowel sounds and their combinations), and that all movements in the universe have sounds associated with them. This in and of itself is why every technique can be called kokyunage.