Does Hayek say that in any reference or letter? How about an interview? I would like to get the reference. Barkley's claim is what Anthony Waterman also made and now also Bruce has made this claim. I am inclined to believe them, but I would just like to see the evidence. Obviously Hayek was deeply familiar with Mill, but on this issue Hayek is particuarly critical of Mill (see his critique of Mill for rational constructivism in The Constitution of Liberty). So I am confused. We know he draws the inspiration for his work on this from Menger, and then from Mises (see his Trend of Economic Thinking paper) in which the distinction between planned and unplanned orders is viewed as critical. When Hayek was the editor of Economica, Polanyi was invited to write an essay on the 'growth of knowledge" in society in which I believe the term spontaneous order is utilized, and the discussion of "spontaneous order" is definitely in Polanyi's The Logic of Liberty. When is the first time Hayek actually uses the term spontaneous order in his writing? He certainly was talking about unplanned orders well before he talked about spontaneous order. I would be appreciative of learning the references. Peter Boettke