“So true is it that all transactions of preeminent importance are wrapt in doubt and obscurity; while some hold for certain facts the most precarious hearsays, others turn facts into falsehood; and both are exaggerated by posterity.”

Source: The God of Jane: A Psychic Manifesto (1981), p. 137

1920s, Sidelights on Relativity (1922)

Soundings and Silences (2016)

1990s, Farewell speech (1999)
Context: Today, on this day that is so extraordinarily important for me, I want to say just a few more personal words than usual.
I want to ask for your forgiveness.
For the fact that many of the dreams we shared did not come true. And for the fact that what seemed simple to us turned out to be tormentingly difficult. I ask forgiveness for not justifying some hopes of those people who believed that at one stroke, in one spurt, we could leap from the gray, stagnant, totalitarian past into the light, rich, civilized future. I myself believed in this, that we could overcome everything in one spurt.
I turned out to be too naive in something. In some places, problems seemed to be too complicated. We forced our way forward through mistakes, through failures. Many people in this hard time experienced shock.

Source: What I Talk About When I Talk About Running

Source: Odyssey of a Friend (1969), p. 52

“The Obscurity of the Poet”, p. 3
Poetry and the Age (1953)
Context: When I was asked to talk about the Obscurity of the Modern Poet I was delighted, for I have suffered from this obscurity all my life. But then I realized that I was being asked to talk not about the fact that people don’t read poetry, but about the fact that most of them wouldn’t understand it if they did: about the difficulty, not the neglect, of contemporary poetry. And yet it is not just modern poetry, but poetry, that is today obscure. Paradise Lost is what it was; but the ordinary reader no longer makes the mistake of trying to read it — instead he glances at it, weighs it in his hand, shudders, and suddenly, his eyes shining, puts it on his list of the ten dullest books he has ever read, along with Moby-Dick, War and Peace, Faust, and Boswell’s Life of Johnson. But I am doing this ordinary reader an injustice: it was not the Public, nodding over its lunch-pail, but the educated reader, the reader the universities have trained, who a few weeks ago, to the Public’s sympathetic delight, put together this list of the world’s dullest books.
Since most people know about the modern poet only that he is obscure—i. e., that he is difficult, i. e., that he is neglected — they naturally make a causal connection between the two meanings of the word, and decide that he is unread because he is difficult. Some of the time this is true: the poet seems difficult because he is not read, because the reader is not accustomed to reading his or any other poetry.

Source: The New Ethics (1907), The Survival of the Strenuous, p. 167