phenomena of modern economic society, its textbooks in economics among the rest. It is a society based on "demand and supply," in politics as in business, and in education as in both. If I might personally incline to have "control" begin with or very soon arrive at the teaching of economics (with myself as controller), I am aware of the personal prejudice involved. In the absence of a workable-looking alternative, I assume that it is "comparatively better" for textbooks to be selected by those who use them. I never meant to imply that my prejudices ought to have been consulted before this book was published or adopted. Those who like it have found something they like, and the mutual pleasure of them and the author must be shared by every liberal spirit. And for the student of phenomena-his interest is identical whether he studies health or disease, and is perhaps rather enhanced by difference of opinion as to which is which. FRANK H. KNIGHT UNIVERSITY OF CHICAGO