„Myšlení je nejtěžší práce, jaká existuje. To je pravděpodobně důvod, proč tak málo lidí myslí.“

Originál

Thinking is the hardest work there is, which is probably the reason why so few engage in it.

Zdroj: As quoted in "My Philosophy of Industry" an interview of Ford by Fay Leone Faurote, The Forum, Vol. 79, No. 4 (April 1928), p. 481;

also in "Thinking Is Hardest Work, Therefore Few Engage in It", San Francisco Chronicle (13 April 1928), p. 25;

both articles are cited as the primary sources of other variants which later arose, in https://quoteinvestigator.com/2016/04/05/so-few "Thinking Is the Hardest Work There Is, which Is the Probable Reason Why So Few Engage In It" in Quote Investigator (5 April 2016)