“Writing is fifty years behind painting.”

Paris Review interview (1996)

A Narrative of Some of the Lord's Dealings with George Müller Written by Himself, First Part.
First Part of Narrative

Source: A History of Economic Thought (1939), Chapter IV, The Classical System, p. 176

Livewire interview (2002)
Context: It's odd but even when I was a kid, I would write about "old and other times" as though I had a lot of years behind me. Now I do, so there is a difference in the weight of memory. When you're young, you're still "becoming", now at my age I am more concerned with "being". And not too long from now I'll be driven by "surviving", I'm sure. I kind of miss that "becoming" stage, as most times you really don't know what's around the corner. Now, of course, I've kind of knocked on the door and heard a muffled answer. Nevertheless, I still don't know what the voice is saying, or even what language it's in.

He was actually quoting Oliver Wendell Holmes, Jr., during an America's Town Meeting of the Air broadcast, at The Town Hall in New York City, (6 January 1938) http://books.google.com/books?id=GekBAAAAMAAJ&q=%22A+good+catchword%22+%22can+obscure+analysis+for+fifty+years%22&pg=A21#v=onepage
Misattributed

2015, Commemoration of the 150th Anniversary of the 13th Amendment (December 2015)
Context: At its heart, the question of slavery was never simply about civil rights. It was about the meaning of America, the kind of country we wanted to be –- whether this nation might fulfill the call of its birth: “We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights,” that among those are life and liberty and the pursuit of happiness. President Lincoln understood that if we were ever to fully realize that founding promise, it meant not just signing an Emancipation Proclamation, not just winning a war. It meant making the most powerful collective statement we can in our democracy: etching our values into our Constitution. He called it “a King’s cure for all the evils.” A hundred and fifty years proved the cure to be necessary but not sufficient. Progress proved halting, too often deferred. Newly freed slaves may have been liberated by the letter of the law, but their daily lives told another tale. They couldn’t vote. They couldn’t fill most occupations. They couldn’t protect themselves or their families from indignity or from violence. And so abolitionists and freedmen and women and radical Republicans kept cajoling and kept rabble-rousing, and within a few years of the war’s end at Appomattox, we passed two more amendments guaranteeing voting rights, birthright citizenship, equal protection under the law.

Quoted by Wendell Willkie during an America's Town Meeting of the Air broadcast, at The Town Hall in New York City, (6 January 1938) http://books.google.com/books?id=GekBAAAAMAAJ&q=%22A+good+catchword%22+%22can+obscure+analysis+for+fifty+years%22&pg=A21#v=onepage.

Les Russes copient les moeurs françaises, mais toujours à cinquante ans de distance.
Vol. II, ch. XXIV
Le Rouge et le Noir (The Red and the Black) (1830)