“830. He thinkes not well that thinkes not againe.”

Remarks to the press after meeting Secretary of State for Transport Norman Fowler (18 June 1981), quoted in Citizen Ken (1984) by John Carvel, p. 107.

Attributed to Orwell by John H. Bunzel, president of San Jose State University, as reported in Phyllis Schlafly, The Power of the Positive Woman (1977), p. 151; but not found in Orwell's works or in reports contemporaneous with his life. Possibly a paraphrase of Orwell's description of the rationale behind Newspeak in 1984.
Disputed

Source: The Perks of Being a Wallflower

Source: The Magic Mountain (1924), Ch. 4
Context: Writing well was almost the same as thinking well, and thinking well was the next thing to acting well. All moral discipline, all moral perfection derived from the soul of literature, from the soul of human dignity, which was the moving spirit of both humanity and politics. Yes, they were all one, one and the same force, one and the same idea, and all of them could be comprehended in one single word... The word was — civilization!

When asked "What should we remember about Bill Clinton? in an interview with George Gurley in The New York Observer (10 January 2005).
2005

Evan Charteris, Life and Letters of Sir Edmund Gosse (1931), p. 197

Rangel (2005) in an interview on New York Public Television (March 28, 2005): On George W. Bush