It’s Difficult to Make Predictions, Especially About the Future

Niels Bohr? Samuel Goldwyn? K. K. Steincke? Robert Storm Petersen? Yogi Berra? Mark Twain? Nostradamus? Anonymous?

Dear Quote Investigator: There is a family of popular humorous sayings about the formidable task of successful prognostication. Here are five examples:

    1. It is difficult to make predictions, especially about the future.
    2. Predictions are hazardous, especially about the future.
    3. It is hard to prophecy, particularly about the future.
    4. It’s dangerous to prophesy, particularly about the future.
    5. Never make forecasts, especially about the future.

Of course, a prediction is inherently about the future, and the modifiers “especially” and “particularly” emphasize the comical redundancy of the statement. These expressions have been attributed to a diverse collection of individuals, including Niels Bohr, Sam Goldwyn, Robert Storm Petersen, and Yogi Berra. Would you please tell me who I should credit?

Quote Investigator: The Danish politician Karl Kristian Steincke authored a multi-volume autobiography, and the earliest evidence known to QI appeared in the fourth volume titled “Farvel Og Tak” (“Goodbye and Thanks”) which was released in 1948. Danish text is followed by an English rendering below. The saying appeared in a section with this title:

Og saa til Slut et Par parlamentariske Sprogblomster

And finally a couple of parliamentary howlers

The saying was spoken during the parliamentary year 1937-1938, and no attribution was specified. Boldface added to excerpts by QI: 1

Det er vanskeligt at spaa, især naar det gælder Fremtiden.

It is difficult to make predictions, especially about the future.

This citation was mentioned in the prominent reference “The Yale Book of Quotations”. 2 More information about Danish citations for this saying is presented in the addendum at the end of this article.

The first appearance in English located by QI was printed in a 1956 academic publication called the “Journal of the Royal Statistical Society. Series A”. This early citation 3 and several others remarked on the Danish language origin of the aphoristic joke: 4

Alas, it is always dangerous to prophesy, particularly, as the Danish proverb says, about the future.

In May 1961 “The Canadian Journal of Economics and Political Science” printed an instance of the saying using the word “hazardous” instead of “dangerous”. Indeed, the phrasing changed over time and was highly variable: 5

“Prediction,” goes an old Danish proverb, “is hazardous, especially about the future.” For the Canadian economy the hazard is especially great.

Here are additional selected citations in chronological order.

Continue reading It’s Difficult to Make Predictions, Especially About the Future


  1. 1948, Farvel Og Tak: Minder Og Meninger by K. K. Steincke, (Farvel Og tak: Ogsaa en Tilvaerelse IV (1935-1939)), Quote Page 227, Forlaget Fremad, København. (Publisher Fremad, Copenhagen, Denmark) (Verified with scans; thanks to a kind librarian at Åbo Akademis bibliotek)
  2. 2006, The Yale Book of Quotations by Fred R. Shapiro, Section Niels Bohr, Quote Page 92, Yale University Press, New Haven. (Verified on paper)
  3. 2012, The Dictionary of Modern Proverbs, Compiled by Charles Clay Doyle, Wolfgang Mieder, and Fred R. Shapiro, Page 206, Yale University Press, New Haven. (Verified on paper)
  4. 1956, Journal of the Royal Statistical Society: Series A (General), “Proceedings of the Meeting”, [Speaker: Bradford Hill], Page 147, Volume 119, Number 2, Blackwell Publishing for the Royal Statistical Society. (JSTOR) link
  5. 1961 May, The Canadian Journal of Economics and Political Science / Revue Canadienne d’Economique et de Science politique, Volume 27, Number 2, “Canada’s Economic Prospects: A Survey of Ten Industries” by Jesse W. Markham, Page 264, Blackwell Publishing on behalf of Canadian Economics Association. (JSTOR) link

I Understand It Brings You Luck, Whether You Believe in It or Not

Niels Bohr? Albert Einstein? Carl Alfred Meier? Apocryphal?

Dear Quote Investigator: There is popular anecdote about a journalist or friend who visited the home of a prominent physicist. The visitor was surprised to find a horseshoe above the front doorway of the scientist’s abode. Tradition asserts that a horseshoe acts as a talisman of luck when placed over a door.

The visitor asked the physicist about the purpose of the horseshoe while expressing incredulity that a man of science could possibly be swayed by a simple-minded folk belief. The physicist replied:

Of course I don’t believe in it, but I understand it brings you luck, whether you believe in it or not.

This slyly comical remark has been attributed to both Niels Bohr and Albert Einstein. I love this entertaining tale, but I am skeptical. Any insights?

Quote Investigator: The earliest match known to QI appeared in “Svenska Dagbladet” (“The Swedish Daily News”) in January 1956. The scientist was identified as Niels Bohr. Boldface added to excepts by QI: 1

Det påstås
att den frejdade atomforskaren Niels Bohr nyligen fick besök av en nyfiken amerikan.

— Professorn har en hästsko ovanför dörren, sa han, Tror professorn på skrock?

Naturligtvis inte. Men jag har hört sägas att en hästsko kan bringa tur även ät folk som inte är vidskepliga . . .

Here is one possible translation into English:

It is alleged
that the celebrated nuclear scientist Niels Bohr was recently visited by a curious American.

— “The professor has a horseshoe above the door,” he said. “Does the professor believe in superstition?”

“Of course not. But I have heard it said that a horseshoe can bring good luck even to people who are not superstitious” . . .

Here are additional selected citations in chronological order.

Continue reading I Understand It Brings You Luck, Whether You Believe in It or Not


  1. 1956 January 4, Svenska Dagbladet (The Swedish Daily News), Det påstås, Quote Page 8, Column 6, Stockholm, Sweden. (Verified with scans)