Who first said "Write what you know"?

One can only write about what they know, even fiction has to have some basis in the Authors reality. You can't make the setting of a story Barcelona if you have no idea what Barcelona is like. Well, of course you can, you can write about anything in whichever way you like. But if to you Barcelona looks like Tokyo then you might as well end all your writing with 'and then I woke up.' This is because the second you begin to write of Barcelona as Tokyo it becomes Tokyo. The trick to writing is to express not to camouflage. When you stray from what you know you are hiding from what it is you're wanting to say by putting the pen to paper. You're hiding from expression. 'Write what you know' isn't a guideline it's a simple truth. You will always write about what you know, it's your only basis of comparison. Writing what you know was not said as encouragement, it was said as a statement. For those who do not have any passion for what they're trying to express never have anything worth saying.

It is mostly linked to Mark Twain.

1) The original expression seems to be untraceable:
- "From what I have found it is considered to be a cliche and an expression that has been around for ages and used by many people. It is also considered to be advice that can be ignored. If you want to write about something that you do not know about you can; just do research and then apply your experiences to it.

When I first read your question I thought immediately of John Dewey. While I do not think that he coined the expression, he did explain that children relate what they learn to the things that they already know and if they know nothing about the topic (have no life experience in it) then they have difficulty learning the material."
Source and further information:
http://www.eduqna.com/Other/905-general-3.html


- "Write what you know.
How many times have you heard that expression? A dozen at least, I'm sure. I know I have—especially in junior high. In fact, I had a grade school English teacher who prefaced nearly every writing assignment she handed out with that advice."
Source and further information:
http://www.candaceirvin.com/writingwyk.html

- "though it is usually said of writing, it could be inferred that he thought of the adage, “write [paint] what you know.”"
Source and further information:
http://en.wikipedia.org/wiki/George_E._Morgan

- "Write what you know. That should leave you with a lot of free time.
Howard Nemerov"
http://www.eduqna.com/Quotations/696-quotations-5.html

- "Most beginning writers - and I was the same - are like chefs trying to cook great dishes that they've never tasted themselves. How can you make a great - or even an adequate - bouillabaisse if you've never had any? If you don't really understand why people read mysteries - or romances or literary novels or thrillers or whatever - then there's no way in the world you're going to write one that anyone wants to publish. This is the meaning of the well-known expression "Write what you know."
Daniel Quinn "
Source and further information:
http://koti.mbnet.fi/pasenka/quotes/q-writ.htm


2) Critique:
- "Bad books on writing and thoughtless English professors solemnly tell beginners to 'Write What You Know', which explains why so many mediocre novels are about English professors contemplating adultery."
Source and further information:
http://en.wikiquote.org/wiki/Joe_Haldeman

- "So how do they get around the golden rule of writing what they know?"
Source and further information:
http://www.fictionfactor.com/articles/whatyouknow.html

- ""Don’t write what you know—what you know may bore you, and thus bore your readers. Write about what interests you—and interests you deeply—and your readers will catch fire at your words." ---Valerie Sherwood"
Source and further information:
http://www.susantaylorbrown.com/quotes.html

- ""Creative writing teachers should be purged until every last instructor who has uttered the words "Write what you know" is confined to a labor camp. Please, talented scribblers, write what you don't. The blind guy with the funny little harp who composed The Iliad , how much combat do you think he saw?"
P.J. O'Rourke"

"Thing is, "write what you know" just means most of the students will never write anything.
Which saves trees."

"Yeah, I had a creative writing class where the mantra was, "write what you know." I think it comes from Solzhenitsyn's nobel prize speech (the one he couldn't leave Russia to give). It's an easy thing to say for someone who spent time in the Gulags and in Stalin's cancer wards."
Source and further information:
http://wizbangblog.com/content/2006/01/10/quote-of-the-da-125.php

- "I subscribe to a third line of thought about writing. It is for me a discovery process. "Write what you know," is tedious work for me: a real slog in deep mud. "Write what you want to read," comes closer to my truth. I'd say, "Write what you want to know."

The injunction, "Write what you know," (received as a kid) was a major barrier to my writing career. It took me many years to get past that one."
Source and further information:
http://curtrosengren.typepad.com/occupationaladventure/2006/01/do_what_you_kno.html

- "Robert Duncan: If I write what you know, I bore you; if I write what I know, I bore myself, therefore I write what I don't know."
Source and further information:
https://notes.utk.edu/Bio/greenberg.nsf/0/7017433cedb3bd7585256a2a0054190a?OpenDocument

- "“Write what you know” is the dictum. What if I, like Socrates have come to realize that all I know is nothing? How does a writer write about nothing without copying Jerry Seinfeld or the eight-fold path of Buddha? Is there a way to write nothing and have it make sense? Is there a formula for enlightenment that assures salvation?"
Source and further information:
http://mountingparnassus.blogspot.com/2005/01/write-what-you-know.html


3) Further information:
http://littlecicero.blogspot.com/2006/01/quote-of-week-19.html
http://cherylreifsnyder.blogspot.com/2007/11/write-what-you-know.html
http://zelophehadsdaughters.com/2007/07/19/write-what-you-know-know-what-you-write-a-review-of-bradford-tices-missionaries/
http://www.randomhouse.com/features/atwaterrhodes/advice.htm