Tom and Lew, note that Hayek returned the favor, saying this about Friedman’s methodological views (Hayek on Hayek, p. 145):

Friedman has this magnificent expository power. He is on most things, general market problems, sound. I want him on my side. You know, one of the things I often have publicly said is that one of the things I most regret is not having returned to a criticism of Keynes’s treatise, but it is as much true of not having criticized Milton’s [Essays in] Positive Economics, which in a way is quite as dangerous a book.