" New Textbooks for the "New" Mathematics http://calteches.library.caltech.edu/2362/1/feynman.pdf", Engineering and Science volume 28, number 6 (March 1965) p. 9-15 at p. 14 
Paraphrased as "Precise language is not the problem. Clear language is the problem."
                                    
“The real problem in speech is not precise language. The problem is clear language.”
            " New Textbooks for the "New" Mathematics http://calteches.library.caltech.edu/2362/1/feynman.pdf", Engineering and Science volume 28, number 6 (March 1965) p. 9-15 at p. 14
Paraphrased as "Precise language is not the problem. Clear language is the problem." 
Context: The real problem in speech is not precise language. The problem is clear language. The desire is to have the idea clearly communicated to the other person. It is only necessary to be precise when there is some doubt as to the meaning of a phrase, and then the precision should be put in the place where the doubt exists. It is really quite impossible to say anything with absolute precision, unless that thing is so abstracted from the real world as to not represent any real thing.Pure mathematics is just such an abstraction from the real world, and pure mathematics does have a special precise language for dealing with its own special and technical subjects. But this precise language is not precise in any sense if you deal with real objects of the world, and it is only pedantic and quite confusing to use it unless there are some special subtleties which have to be carefully distinguished.
        
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Richard Feynman 181
American theoretical physicist 1918–1988Related quotes
Source: "Quotes", The Great Code: The Bible and Literature (1982), Chapter Three, p. 56
Public Talks, The State of the Onion 10
"The Concept of Truth in Formalized Languages" (1931) in Logic, Semantics, Metamathematics: Papers from 1923 to 1938 (1956) Tr. J. H. Woodger.
“A precise language awaits a completed metaphysics.”
1920s, Process and Reality: An Essay in Cosmology (1929)
                                        
                                        The Art of Doing Science and Engineering: Learning to Learn (1991) 
Context: The fundamentals of language are not understood to this day.... Until we understand languages of communication involving humans as they are then it is unlikely many of our software problems will vanish.
                                    
Rob Pike (2004) in interview http://interviews.slashdot.org/article.pl?sid=04/10/18/1153211&tid=189 at slashdot.com, Oct 18 2004
                                        
                                        Никаких философских проблем нет, есть только анфилада лингвистических тупиков, вызванных неспособностью языка отразить Истину. 
The Sacred Book of the Werewolf [Священная Книга Оборотня], p. 226. (2004, translated by Andrew Bromfield in 2008)