[Stroustrup, Bjarne, The C++ Programming Language, 712]
The Soul of a Butterfly, 2004
Variant: All through my life I have been tested. My will has been tested, my courage has been tested, my strength has been tested. Now my patience and endurance are being tested.
Source: The Soul of a Butterfly: Reflections on Life's Journey
As cited in: Allen Kent, James G. Williams (1995), Encyclopedia of Computer Science and Technology: Volume 32. p. 187
Principles of program design, 1975
Think Better: An Innovator's Guide to Productive Thinking
Quoted in the IBM employee magazine Think in 1979. Cited by his Associated Press obituary http://www.msnbc.msn.com/id/17704662/
“We have got the greatest testing program anywhere in the world.”
2020, June 2020
“So-called alternative medicine either hasn’t been tested or it has failed its tests.”
The Enemies of Reason (August 2007)
Context: If any remedy is tested under controlled scientific conditions and proved to be effective, it will cease to be alternative and will simply become medicine. So-called alternative medicine either hasn’t been tested or it has failed its tests.
Appel, Tim. Noem on Bailouts http://www.rapidcityjournal.com/vmix_64cb45d2-d71d-11df-8a99-001cc4c002e0.html, Rapid City Journal, October 13, 2010.
“Program testing can be used to show the presence of bugs, but never to show their absence!”
Dijkstra (1970) " Notes On Structured Programming http://www.cs.utexas.edu/users/EWD/ewd02xx/EWD249.PDF" (EWD249), Section 3 ("On The Reliability of Mechanisms"), corollary at the end.
1970s
Variant: Program testing can be a very effective way to show the presence of bugs, but it is hopelessly inadequate for showing their absence.
“No concrete test of what is really true has ever been agreed upon.”
Source: "The Will to Believe" p. 15 http://books.google.com/books?id=Moqh7ktHaJEC&pg=PA15
Source: 1890s, The Will to Believe and Other Essays in Popular Philosophy (1897)
