PeterR

Hagen - I read your online material and could not help thinking that you were lumping several different Buddhist traditions under the term Zen. Is that a fair statement? No issue if that is the case - that is just semantics.

Quite a few martial art concepts are described in Buddhist terms (as covered in your book) and the connections in my opinion predate the rise in popularity of Zen Buddhism. But since Zen is a form of Buddhism it stands to reason that the overlap remains.

I don't think practices or attitudes unique to Zen Buddhism had any effect on aikido specifically, at least at the level of the Ueshiba(s) or the ancestor arts. I also think that's true of other Japanese marital arts although perhaps you can find exceptions.