“Did you hear about the mathematician who was afraid of negative numbers? He would stop at nothing to avoid them.” (This joke is all over the Internet, and I’m not sure where the original source would be).
“All scientific work is incomplete, whether it be observational or experimental. All scientific work is liable to be upset or modified by advancing knowledge. That does not confer upon us a freedom to ignore the knowledge we already have, or to postpone the action that it appears to demand at a given time. Who knows, asked Robert Browning, but the world may end tonight? True, but on available evidence most of us make ready to commute on 8:30 the next day.” Sir Austin Bradford Hill, as quoted in his landmark 1965 paper on causation.
“The most challenging thing in the world is not to learn fancy technologies, but control your own wild heart.” Yihui Xie, as quoted in Appendix C of Authoring Books wtih R Markdown.
Exploratory data analysis is an attitude, a state of flexibility, a willingness to look for those things that we believe are not there, as well as the things we believe might be there. John Tukey, as quoted in “Nonparametric statistical data modeling: comment.” J Am Stat Assoc 1979, 74, 121-122.
“The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from some data.” John Tukey, as quoted in “Sunset Salvo.” The American Statistician 1986, 40(1), 72-76.
“In a world where the price of calculation continues to decrease rapidly, but the price of theorem proving continues to hold steady or increase, elementary economics indicates that we ought to spend a larger and larger fraction of our time on calculation.” John Tukey, as quoted in “Sunset Salvo”, The American Statistician 1986; 40(10): 72-76.
“Without data, you’re just another person with an opinion.” W. Edwards Deming. As quoted at https://www.goodreads.com/author/quotes/310261.W_Edwards_Deming.
Referring to anecdotal data: “That’s not an experiment you have there, that’s an experience.” Sir Ronald A. Fisher.
…when people assume that the Excel output is enough. I think of all the research papers in economics where the authors must have spent dozens of hours trying all sorts of different model specifications, dozens of hours writing and rewriting the prose of the article, . . . and 15 minutes making the graphs.” Andrew Gelman, quoted at http://andrewgelman.com/2009/04/22/more_on_data_vi/.