“Journalism — a profession whose business it is to explain to others what it personally does not understand” is a quotation credited to Lord Northcliffe (1865-1922), a British newspaper and publishing magnate, The quotation and credit were cited in Speaker’s Handbook of Epigrams and Witticisms (1955), but the quotation is seemingly much older. Lord Northcliffe’s quotation—unflattering that it is—is one of the most popular quotations about the journalism profession.
 
   
Wikiquote: Alfred Harmsworth, 1st Viscount Northcliffe
Alfred Charles William Harmsworth, 1st Viscount Northcliffe (1865–1922) was a British newspaper and publishing magnate.
 
His company Amalgamated Press employed Arthur Mee and John Hammerton, and the Amalgamated Press subsidiary the Educational Book Company published the Harmsworth Self-Educator, The Children’s Encyclopædia, and Harmsworth’s Universal Encyclopaedia.
 
During his lifetime, he exercised vast influence over British popular opinion. Megalomania contributed to a nervous breakdown shortly before his death.
 
Google Books
Speaker’s Handbook of Epigrams and Witticisms
By Herbert V. Prochnow
New York, NY: Harper
1955
Pg. 157:
Journalism — a profession whose business it is to explain to others what it personally does not understand. Lord Northcliffe
 
21 April 1973, Winnipeg (Manitoba) Free Press, “Word Wise” by Larry Geller, Saturday Magazine, pg. 2, col. 4:
Lord Northcliffe: “journalism—a profession whose business it is to explain to others what it personally does not understand.”
 
23 November 1978, Dallas (TX) Morning News, “Who Said That?.” pg. 2D, col. 3:
Journalism: A profession whose business it is to explain to others what it personally does not understand.—Lord Northcliffe.
 
Google News Archive
30 August 1980, Vancouver (British Columbia) Sun, “Let’s Rip Off The Masks,” pg. 5, col. 1:
John Kirkwood’s hyperbole (Abolish the Scientists, Page Five, Aug. 7) brought to mind Lord Northcliffe’s conception of journalism: a profession whose business it is to explain to others what it personally does not understand.
(Letter by Steven Kehl—ed.)
 
Google News Archive
22 January 1989, TimesDaily (Northwest Alabama),“From the Editor” by Bruce Gaultney, pg. 12A, col. 4:
Someone once defined journalism as, profession whose business it is to explain to others what it personally does not understand.”
 
I almost agree with that statement, but I would amend it to say journalists explain to others what they first have had to research to understand themselves.
   
Google Books
The Best of Financial Mail’s:
Did You Hear?
Compiled by David Furlonger
Cartoons by Walter Pichler
Cape Town: Tafelberg
1992
Pg. 15:
August 6, 1982: Of the late Lord Northcliffe’s definition of journalism? “A profession whose business it is to explain to others what it personally does not understand.”