[Ads-l] Adage Origin: Assumption is the mother of all foul-ups (screw-ups, mess-ups, fuck-ups, mistakes)

[ADSGarson O'Toole]

The saying in the subject line has been credited to U.S. interior
designer Angelo Donghia, U.S. military parachutist Bill Gatter,
political scientist Eugene Lewis Fordsworthe (who may not exist), and
others.

I received a request to investigate. There are several versions of
this saying which makes it difficult to trace. The earliest match I
found appeared in "The Sun" newspaper of Baltimore, Maryland in July
1972. A political operative in a U.S. presidential campaign employed
the saying:

[ref] 1972 July 1, The Sun, Youth image follows candidate on trips by
Adam Clymer (Washington Bureau of The Sun), Quote Page A9, Column 1,
Baltimore, Maryland. (ProQuest) [/ref]

[Begin excerpt]
They would not be traveling anywhere if it were not for Stephen
Robbins, 30, the chief advance and scheduling man, who breezily
advises his even younger aides: "Don't assume: assumption is the
mother of foul-ups."
[End excerpt]

The above citation suggests that Stephen Robbins may have coined the
adage, but I believe it is more likely that the saying was already in
circulation, and the creator was anonymous. Future researchers may
uncover earlier evidence.

Here is a link to the Quote Investigator article:
https://quoteinvestigator.com/2025/09/29/assumption-mother/

Earlier citations, interesting material, and feedback would be welcome.
Garson

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