“Political questions, if you go back thousands of years, are ephemeral, not important. History is the same thing over and over again.”

Source: A Thousand Splendid Suns

XII. 453–454 (tr. Samuel Butler).
Odyssey (c. 725 BC)

Brown did include this quote in her book Sudden Death (Bantam Books, New York, 1983), p. 68, but it appears she was just paraphrasing a quote that had already been written elsewhere. The earliest known appearance of a similar quote is the "approval version" of the Narcotics Anonymous "Basic Text" released in November 1981, which included the quote "Insanity is repeating the same mistakes and expecting different results." A PDF scan of the 1981 approval version can be found here http://www.nauca.us/wp-content/uploads/2015/04/1981-11-Basic-Text-Approval-Form-White.pdf, with the quote appearing on p. 11 (p. 25 of the PDF), at the end of the fourth paragraph (which begins "We have a disease; progressive, incurable and fatal"). More in this article https://quoteinvestigator.com/2017/03/23/same/ on Quote Investigator website.
Misattributed

Source: The Brass Verdict

Source: Along for the Ride

Life and Habit http://www.gutenberg.org/dirs/etext04/lfhb10h.htm, ch. 5 (1877)
Context: "Words, words, words," he writes, "are the stumbling-blocks in the way of truth. Until you think of things as they are, and not of the words that misrepresent them, you cannot think rightly. Words produce the appearance of hard and fast lines where there are none. Words divide; thus we call this a man, that an ape, that a monkey, while they are all only differentiations of the same thing. To think of a thing they must be got rid of: they are the clothes that thoughts wear—only the clothes. I say this over and over again, for there is nothing of more importance. Other men's words will stop you at the beginning of an investigation. A man may play with words all his life, arranging them and rearranging them like dominoes. If I could think to you without words you would understand me better."

On the failure of Hitler and his advisors to face realities of various situations, especially those of the military on the Eastern Front, in Panzer Leader (1952), Ch. 6 : The Campaign in Russia, p. 190
Context: To imitate the ostrich in political matters has never been a satisfactory method of avoiding danger; yet this is what Hitler, as well as his more important political, economic and even military advisers, chose to do over and over again. The consequences of this deliberate blindness in the face of hard facts were devastating; and it was we who now had to bear them.

Part One, Eight
The Dud Avocado (1958)