“When someone persuades me that I am wrong, I change my mind. What do you do?”
— John Maynard Keynes, 1921, A Treatise on Probability. London: Macmillan
UPDATE: See the comments for a discussion as to whether Keynes really wrote or uttered these words.
by Bruce Bartlett on March 4th, 2011 at 16:24
I just searched through that book using Google books and could not find that quote.
by Austin Frakt on March 4th, 2011 at 19:59
@Bruce Bartlett – Here’s the scoop. I saw it in Bernstein’s “Against the Gods.” His endnote says it appears in Moggridge, Vol. X p. 440 and then says “see also Keynes 1921, p. 408.”
Here’s the rest of the Moggridge citation: 1972. the Collected Writings of John Maynard Keynes. New York: St. Martin’s Press.
@Addi – Maybe it was misquoted in my source. I actually would prefer it not use “persuades” but, rather, “shows.” As written it is tautological.
If anyone can verify the quote and source, please let me know.
by Addi on March 4th, 2011 at 17:33
I had always heard this quote as, “When the facts change, I change my mind.”
by wkj on March 4th, 2011 at 17:39
The same apocryphal quote appears on page 100 of “The Birth of Plenty” by William Bernstein. A footnote to the quote indicates that Bernstein confirmed with both Donald Moggridge (editor of Keynes’ Collected Works) and Lord Robert Skidelsky (author of the 3-volume biography of Keynes) that the words were never uttered by Keynes.