I wrote a book about life force ideas around the world, and found that they can be sorted into categories. One of those categories is air based life force ideas, such as qi, ki, prana, spirit, ruach, and so on.
These concepts have great similarities, so I dare say that they have more to do with common human traits and circumstances than with cultural differences.
Here's the book, by the way:
Well I worked about the relationship of qi, ki and the christian "Holy Ghost" i.e. ruah, pneuma.
Because they are air based life force ideas as you call it, I assumed to find more similaryties then differences. Different terms, same concept I thought.
But I found I wasn't wright. You are wright: There are a lot similarities but, there are also some fundamental differences.
You can't seperate the understanding of ruah and pneuma from being the pneuma or ruah of god. Of him alone. This pneuma or ruah is send to his creation but it is not part it as ki/qi is:
Only god has ruah/pneuma. human beings / animals / trees have not. (Do we "have" ki?)
You can't direct ruah/pneuma as you can ki. You can't manage ruah/pneuma as you can ki in Shiatsu or Aikido.
You can't eat it or inhale it as you can ki.
You can't send it, as you can ki.
When God gives Adam live (Gen 2, 7) he "breathes into his nostris the breath of live" which to me is an equivalent of ki/qi the term ruah is not used in the hebrew text.
Or - am I wrong?