DEVIL IS IN THE DETAILS - The "Random House Dictionary of Popular Proverbs and Sayings" by Gregory Y. Titelman (Random House, New York, 1996) shows this phrase as a variation of "God is in the details - Whatever one does should be done thoroughly; details are important. The saying is generally attributed to Gustave Flaubert (1821-80), who is often quoted as saying, 'Le bon Dieu est dans le detail' (God is in the details). Other attributions include Michelangelo, the architect Ludwig Mies van der Rohe, and the art historian Aby Warburg. 'The Devil is in the details' is a variant of the proverb, referring to a catch hidden in the details. 'Governing is in the details''and 'The truth, if it exists, is in the details' are recent variants. Listed as an anonymous saying in the sixteenth edition of Barlett's 'Familiar Quotations,' edited by Justin Kaplan." - http://www.phrases.org.uk/bulletin_board/24/messages/694.html
The Devil is in the Details.
When I was in High School, (never mind the year!), Mrs. Brenneman (who at the time was Miss Rosenfeld), was my English teacher. She gave us an assignment for creative writing. And we were each assigned one ingredient to illustrate the story. Some of us brought in loaves of bread, some had to bring in jars of peanut butter (and some jelly.)
The assignment seemed straightforward enough; an alien has landed on earth, and is hungry. Describe how to make a peanut butter and jelly sandwich. She did warn us to use “...specific details.”
We went home, wrote our stories, and brought our assigned ingredients (I seem to recall mine was a loaf of bread, but you know what they say about the mind.... no wise cracks from the “Peanut” butter gallery!). And I thought I had it made... how wrong I was!
So Miss Rosenfeld chose a story, and had all the ingredients on one table, and a second empty table to work on. As she read each story, she would do exactly what was directed, so there were a lot of unopened jars on top of unopened loaves of bread. We were all laughing hysterically. I knew mine would get such treatment!
She told us that, “Remember they don't know how to extrapolate from your directions how to;
open the loaf of bread, taking out the two slices of bread, putting those slices of bread on a plate (its that round flat thing on the table), then open the jar of peanut butter, place the knife in the brown substance (peanut butter), and move the knife around, to mix the peanut butter, then take the knife with a scoop of the peanut butter, and wipe it on the bread. Then put the knife back in the peanut butter, take it out, and put more on the other slice of bread. Now take the jar of jelly, open it, and take another knife, scoop some up, and put it on the first slice of bread on top of the peanut butter. Now you put the two slices with the peanut butter and jelly side facing each other, and put them together.” Of course I'm paraphrasing, but that was the gist of what she said.
I've always remembered that lesson for writing, though if I were doing it now, I'd be the smart-ass and ask, “But what if they are allergic to peanuts?” Detention here I come!