Although I do not know the exact original text to which you (or Mr Stevens) refer, Rudy, but the phrase that I most commonly have run across that was used by the founder (eg in "Takemusu Aiki") that would correspond, in my mind, to the phrase "the art of peace" would be 「和合
」("wagou no michi").
Hope that helps,
The source I originally used was at http://omlc.ogi.edu/aikido/talk/osen...ace/index.html
quotation # 01 but no footnotes on sources are provided by either the original translator or the website indexing the quotations.
After reading your post I found http://books.google.com/books?id=Mxj...page&q&f=false
Can I safely assume the calligraphy signed by OSensei on page 9 of that text are the ones he would have translated as "The Art of Peace"? I think it may be the most likely source of the kanji I'm looking for. However, if OSensei delivered his teachings primarily through an oral tradition and used different kanji to express the same concept in different contexts then the issue may require more study. I'm guessing there's more than one thesis out there which touches on this topic.