From Davids description sound like Ki leads mind then.
Not at all, Graham.
Normally, there would be no division and the mind and ki would work together well enough for most people to live an ordinary life.
But modern society puts all the emphasis on the mind (calculation and intellect) over both body and "emotions" (all the ki functions of feeling and movement that aren't directly useful for business calculation).
When the mind is so completely alienated from the very ki of which it is made, then it's necessary for the mind perhaps not to be led by the ki, but to follow the ki like a horse tamer. If you read "The Man Who Listens to Horses," it's sort of like that. You only get to understand horses by hanging with them and paying very close attention to them over a long period. To get to know your ki, your mind has to get to know it. That means not making it do what you want it to do, but finding out what it is, what it's about and what it wants to do, as well as how it does that. And after you know it so well, you can befriend it (since it is actually yourself) and if you have enough mental development, you can begin to lead it.
How can you lead something you really don't understand at all?
But here is an important point. After following the ki around and hanging out with it and watching its tricks, one may or not recognize that ki comes from kokoro. Then there is the question of how much influence the rational mind should have over the natural heart. As a literary artist, this has been a question I've worked on for forty years and it has filtered through my approach to martial arts as well. Who is to rule the heart? Whose business it is?
Well, here we find another continuum and the poles are "Pure Heart" and "Defeat the Self."
The danger of the "pure heart" side is disintegration into passions or frivolity. The danger of the "Defeat the Self" side is that you will defeat yourself.
Both ways are bad for the ki and for the whole life.
The "pure heart" way, without rational strength may indeed end up led by ki, attributing everything to ki and eschewing technique.
The "defeat the self" type tends to put everything on technique and uses adherence to technique as a "spiritual" practice to take up for the lack of a spirit.
The answer is, indeed, for the rational mind to understand kokoro and direct it from passion or frivolity to a middle way, not to the other extreme of "defeat the self," but to the middle place called "amenominakanushi," or "the boss." This is the place of "winning the self," not defeating self.
Here the kokoro is "tamed" by the rational mind, like a lion domesticating itself, so that the ki issuing from kokoro is strong and smooth. And the mind that conditions the ki so is then fit to direct that ki to wherever.
And of course, this cannot be done entirely in the mind and ki. It has to been actively done in the body, so the body is in pretty good condition and is able to respond to (and bear) the leading of the ki, as directed by the balanced mind.
So, no, it isn't that the mind follows the ki. It only follows the ki long enough to know it completely. After that, it directs and trains the ki.
Hope that makes it clearer.