Who first said: “We must keep an open mind, but not so open that our brains fall out”?

I have heard the quote in the title attributed to all sorts of people, ranging from mathematician Alan Ross Anderson to Mark Twain to Prince Charles [OK, the sophomoric jokes write themselves]. But who really said this?

Quoteinvestigator did the legwork and also cites another article researching the origin of the quote.

Let us keep our minds open, by all means, as long as that means keeping our sense of perspective and seeking an understanding of the forces which mould the world. But don’t keep your minds so open that your brains fall out! There are still things in this world which are true and things which are false; acts which are right and acts which are wrong, even if there are statesmen who hide their designs under the cloak of high-sounding phrases.

— Walter Kotschnig November 8, 1939

Now, who is Walter Kotschnig? This American academic and diplomat of Austrian-Jewish origin has a fairly detailed bio in the German-language Wikipedia, but none in the English version. A brief summary:

He was born in the historical town Judenburg in Steiermark/Styria, Austria as the son of a school principal. The town name is first documented in 1074: it was an important commercial center at the time and, as the name suggests, had a significant Jewish community (which was expelled in 1496). During the Third Reich, there were attempts to change the “embarrassing” name, but a decision was postponed until after the “Endsieg” (final victory), which thank G-d never came.

Kotschnig started his university studies in nearby Graz. As he became ill with tuberculosis, he was briefly cared for by an American relief organization based in the Netherlands: the experience made him passionate about international collaboration. Upon obtaining his doctorate in political science at the U. of Kiel, Germany in 1924 and marrying (to psychologist Elinid Prys), he took a position with the International Student Service in Geneva, and from 1927 until 1934 served as secretary-general of the organization. Subsequently, he worked for the League of Nations (the interbellum predecessor of the UN) as director of the High Commission for German Refugees. In 1936 he emigrated with his family to the USA, where he took up teaching positions at two of the “Seven Sisters” women’s colleges, Smith College and Mount Holyoke. In addition, he published scholarly papers on education policy planning. He became a US citizen in 1942, published a book with proposals for democratic education reforms in formerly fascist countries, and in 1944 was involved in the planning of the Dumbarton Oaks conference, which was the cradle of the UN. In 1947 he became the head of the International Organizations desk at the US State Department, to eventually rise to the position of Assistant Secretary of State (1965-1971).

At any rate, on November 8, 1939, he gave a speech at Smith College in honor of the upcoming Armistice day, where he made the above remark. The manuscript of his speech has been found in his collected papers at SUNY Albany.

The speech was later reported on in an article in the Smith Alumnae Quarterly [“Chapel and Assembly Notes”, Vol. 31(2), p. 153 (1940)] where the quote first appears in print in that form.

Tim Farley in his article does, however, note an earlier quote in a Yale Law Journal article by law professor Max Radin, “On Legal Scholarship,”  http://dx.doi.org/10.2307/791732  ) that may have been a direct inspiration.

[Practical gentlemen] have a number of bitterly sarcastical comments on persons whose minds are so open that their brains fall out.

Radin may have borrowed it in turn from somebody else, but Kotschnig is clearly the first documented person to use the quote in substantially its present form.