To Err Is Human, But a Human Error Is Nothing To What a Computer Can Do If It Tries

Agatha Christie? Bill Vaughan? Anonymous?

Dear Quote Investigator: Previously you examined a humorous statement from columnist Bill Vaughan about the electronic beasts that control so much of our lives:

To err is human, to really foul things up requires a computer.

I think that the famous mystery writer Agatha Christie said something very similar. Would you please help me to find a citation?

Quote Investigator: In 1969 Agatha Christie published “Hallowe’en Party” featuring her masterful Belgian detective Hercule Poirot. The character Mrs. Oliver tells Poirot that he is acting like a computer by programming himself with data about the crime that occurred. Emphasis added to excerpts by QI: 1

“It is certainly an idea you have there,” said Poirot, with some interest. “Yes, yes, I play the part of the computer. One feeds in the information—”

“And supposing you come up with all the wrong answers?” said Mrs. Oliver.

“That would be impossible,” said Hercule Poirot. “Computers do not do that sort of thing.”

“They’re not supposed to.” said Mrs. Oliver, “but you’d be surprised at the things that happen sometimes. My last electric light bill, for instance. I know there’s a proverb which says, ‘To err is human’ but a human error is nothing to what a computer can do if it tries.”

The quip by Bill Vaughan is discussed here. It appeared in April 1969, 2 and Christie’s book was published the same year, but writing a book is often a lengthy endeavor, and QI does not know precisely when Christie composed her computer remark. Thus, the chronology is uncertain.

Below are additional selected citations in chronological order.

These mordant comments allude to a remark from the famous 18th century English poet Alexander Pope: To Err is Human; to Forgive, Divine. But Pope’s actual words in 1711 were slightly different since the preferred spelling of “human” has changed: 3

Good‐Nature and Good‐Sense must ever join; To Err is Humane; to Forgive, Divine.

Christie’s remark has continued to circulate. For example, in 2014 the Associated Press news service published the following: 4

Thought for Today: “I know there’s a proverb which says ‘To err is human,’ but a human error is nothing to what a computer can do if it tries.” — Dame Agatha Christie, English mystery writer (1890-1976)

In conclusion, Agatha Christie should be credited with the statement she published in 1969.

(Great thanks to John S. whose inquiry led QI to formulate this question and perform this exploration.)


  1. 1970 (Copyright 1969), Hallowe’en Party by Agatha Christie, Quote Page 35, Pocket Books, New York. (First published in 1969; this is 1970 paperback edition) (Verified with scans)
  2. 1969 April 2, Free Lance-Star, Senator Soaper [Free standing quote], Page 1, Column 2, Fredericksburg, Virginia. (Google News archive)
  3. 1711, An Essay On Criticism by Alexander Pope, Page 30, Printed for W. Lewis in Russel-Street, Covent-Garden, London. (Google Books full view) link
  4. 2014 January 22, The Index-Journal, Daybreak: Today in History by the Associated Press, Quote Page 6A, Column 5, Greenwood, South Carolina. (Newspapers_com)