Quotes Uncovered: Who Said Data Kills?

Fourteen weeks ago I invited readers to submit quotations for which they wanted me to try to trace the origins, using The Yale Book of Quotations and more recent research by me. Hundreds of people have responded via comments or e-mails. I am responding as best I can, a few per week.
Eric asked:

I had a friend who was absolutely convinced he came up with the phrase “If you play with fire, you’re gonna get burned.” He claims he had never heard it before, and just thought it up one day. No amount of evidence could sway him otherwise.

The Yale Book of Quotations lists this under “Proverbs,” and notes that it appears, in the form “If people will play with fire, they must expect to be burned by it some time,” in R. H. Thorpe, The Fenton Family (1884).

wrc asked:

“The murder of a beautiful theory by a gang of brutal facts” — I have heard it attributed to Herbert Spencer, but also that it was not Spencer.

The YBQ credits this to Thomas H. Huxley, who wrote in “The Study of Zoology” (1861): “The great tragedy of Science — the slaying of a beautiful hypothesis by an ugly fact.”
Daniel asked:

My roommate always uses the phrase “Good artists borrow, great artists steal.” He cannot figure out who said it, except that it was said by somebody important. Do you have any ideas?

Maybe he is thinking of T. S. Eliot‘s line, “Immature poets imitate; mature poets steal.” (The Sacred Wood [1920]).
JBT asked:

“From hell,” as in “She was the nanny from hell.”

This one is particularly dear to my heart. An episode of the TV show Curb Your Enthusiasm was devoted to comedian Richard Lewis‘s quest to convince Bartlett’s Familiar Quotations to acknowledge him as the coiner of this idiom. Bartlett’s, which has little interest in new quotations or in researching quotation sources, refused to comply with Lewis’s desires. The Yale Book of Quotations, however, cites the Chicago Tribune, April 20, 1986, quoting Lewis describing himself as the “comedian from hell,” with the annotation that this is the “earliest documented example of the expression ‘from hell’ referring to a person.”
Do any readers have any other quotations whose origins they would like me to attempt to trace?