Zaadz.com says this is a quote of Jan van de Snepscheut, a dutch Mathematician. http://www.zaadz.com/quotes/authors/jan_van_de_snepscheut/
"It may come out all right in practice, but it'll never work in theory!"
"In theory, practice is simple." (Source: TrygveReenskaug)
In theory, this quote actually originated somewhere. In practice it is impossible for us to know... -- JohnClonts
In theory, theory and practice are the same. In practice, they are not. -- AlbertEinstein
More "theory" quotes at... http://www.quotemeonit.com/theory.html [BrokenLink? All I see is an advertisement on this page.]
I rather like RobertGrossblatt?'s variation: theory and reality are only theoretically related. It's vastly more succinct and far more pithy.
Clearly what we need is a theory compiler that automatically transforms to practice on its output! -- DougMerritt (a big fan of automation and compilers, but a little hazy on practicality, thus the wish)
"The DifferenceBetweenTheoryAndPractice is in theory somewhat smaller than in practice" was my signature on the usenet for many years. I know I've heard it somewhere, but I can't tell where. Does anyone know? -- FrankWestphal
"Beware of bugs in the above code; I have only proved it correct, not tried it." - Donald E. Knuth (DonKnuth)
Nonsense. If reality disagrees with theory, reality wins. Always. That's science.
Maybe a DifferenceBetweenTheoryAndBelief? -- an exploration of the PhilosophyOfScience?
I don't quite feel like starting those pages, but I can recommend an excellent read:
The Meaning of It All By RichardFeynman
ISBN 0738201669 Collection of Lectures
"Reality wins. Always. That's science."
In theory, that's science. But in reality, science is sometimes practiced differently. -- FalkBruegmann
Some miscellaneous thoughts on theory and reality.
I really need to graduate. I've lost the ability to discern theory from practice