"After all, why should there be another Milton Friedman in the future when none had appeared before him? I suppose the likeliest candidate for that role in the past was J. M. Keynes. He, too, had an extraordinarily sharp and quick mind, according to all reports of contemporaries, and appears to have had the same facility—and joy—in debate. But there is a vital difference: Keynes was not an ideologue. Of course he took strong positions, and had no lack of self-confidence. But Keynes avoided extremes, and changed his mind often. The usual complaint was that he was too flexible. There was a joke that a group of 12 economists would have 13 opinions on any significant issue, because Keynes would have two. You would never read Friedman’s name into that sentence."
- Robert Solow, May 2013, "Why is there no Milton Friedman today?"