The last chapter of Menger's Principles is dedicated to the problem of money. There he uses an expression like "naturgemaesses Product der menschlichen Wirthschaft" (natural process of human economy), but as far as I know, he does not seem to be using a phrase "spontane Ordnung" (spontaneous order). The same can be said of his next methodological work. Of course all of this does not deny that Menger was a source of Hayek's arguments together with various Scottish Enlightenment authors, including A. Smith. Anyway, "spontaneous" and "order" are bread and butter words in any western languages. I suppose that it was very easy for Hayek to coin the new (?) terminology "spontaneous order". Yukihiro Ikeda