“It is characteristic of the design of scientific research that exquisite attention is devoted to methodological problems that can be solved, while the pretense is made that the ones that cannot be solved are really nothing to worry about. On the one hand, biologists will apply the most critical and demanding canons of evidence in the design of measuring instruments or in the procedure for taking an unbiased samples of organisms to be tested, but when asked whether the conditions in the laboratory are likely to be relevant to the situation in nature, they will provide a hand-waving intuitive argument filled with unsubstantiated guesses and prejudices because, in the end, that is all they can do.”

Attributed

letter to Koichi Mano (3 February 1966); published in Perfectly Reasonable Deviations from the Beaten Track: The Letters of Richard P. Feynman (2005), p. 198, 201
also quoted by Freeman Dyson in "Wise Man" http://www.nybooks.com/articles/18350, The New York Review of Books (20 October 2005)
Context: The worthwhile problems are the ones you can really solve or help solve, the ones you can really contribute something to. … No problem is too small or too trivial if we can really do something about it. You say you are a nameless man. You are not to your wife and to your child. You will not long remain so to your immediate colleagues if you can answer their simple questions when they come into your office. You are not nameless to me. Do not remain nameless to yourself — it is too sad a way to be. Know your place in the world and evaluate yourself fairly, not in terms of the naïve ideals of your own youth, nor in terms of what you erroneously imagine your teacher's ideals are.

Classic, Romantic, Modern (1961), ch. I: "Romanticism — Dead or Alive?"

Source: Seven Years in Tibet

Kaoru Ishikawa in: Annual Quality Congress Transactions, (1981), p. 130

Source: Collapse: How Societies Choose to Fail or Succeed (2005), Chapter "The world as a polder: what does it all mean to us today?", section "Reasons for hope" (Penguin Books, 2011, pages 521-522, ISBN 978-0-241-95868-1.

as stated in 1796 before the National Institute of Sciences and Arts in Paris, concerning fossil elephants.

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