No argument there, but don't the Chinese say that someone "has" jin or doesn't "have" it? Since I've read that jin = li (muscular force) + qi (ki), it seems to me that it's something one has to create within oneself. Those who haven't done that work (or who don't even know of it) don't "have" jin, wouldn't you say? And since you pretty much equate jin with aiki, it seems reasonable to say someone "has" or "does not have" aiki.
What I'd really like is your comments on the tai chi ruler thread.
I would just add that there is wai (external) jin and nei (internal) jin. they are not the same externally i would agree with what you have said "jin = li (muscular force) + qi (ki)" internally muscular force should not be used. li (muscular force) can be broken (like a stiff piece of wood) true jin is unbreakable (like a fast flowing river).