… is from page 142 of Capital, Expectations, and the Market Process - a 1977 collection, edited by Walter Grinder, of some of Ludwig Lachmann’s finest academic papers; this quotation is from Lachmann’s 1954 article “Some Notes on Economic Thought, 1933-1953“:
It is difficult to avoid the impression that Keynes introduced expectations whenever it suited his argument, and left them out when it did not. Furthermore, in his Chapter 12 on “The State of Long-Term Expectation,” the famous diatribe against the Stock Exchange, it becomes painfully evident that Keynes failed to grasp the nature of the problem posed by the existence of inconsistent expectations. Instead of studying the process by which men in a market exchange knowledge with each other and thus gradually reduce the degree of inconsistency by their actions, he roundly condemned the most sensitive institution for the exchange of knowledge the market economy has ever produced!
It should be noted that Lachmann was more favorably disposed to Keynes’s economics than are most other economists who are heavily influenced by the Austrian tradition.