… is from pages 9-10 of Bruce Caldwell’s superb 2004 intellectual biography of Hayek, Hayek’s Challenge (original emphasis):
Whatever the many differences that separated [J.M.] Keynes from [Oskar] Lange might be, both of them saw a machine that had broken down when they looked at the economy. This provided another puzzle for Hayek, for, when he looked at the economy, he saw an organism that sometimes failed to work, to be sure, but at other times was able to coordinate the activities of millions of independent human beings…. He came to the conclusion that even the most advanced theories of the time had failed to capture the central features of a market economy, in particular the way it was able to coordinate dispersed knowledge and allow that knowledge to be used by others.