“4867. There cannot be a more intolerable Thing than a fortunate Fool.”

"As I Please," Tribune (8 December 1944)^{http://alexpeak.com/twr/tdoaom/}
"As I Please" (1943–1947)
Context: The important thing is to discover which individuals are honest and which are not, and the usual blanket accusation merely makes this more difficult. The atmosphere of hatred in which controversy is conducted blinds people to considerations of this kind. To admit that an opponent might be both honest and intelligent is felt to be intolerable. It is more immediately satisfying to shout that he is a fool or a scoundrel, or both, than to find out what he is really like. It is this habit of mind, among other things, that has made political prediction in our time so remarkably unsuccessful.

As quoted by F. R. Moulton, Introduction to Astronomy (New York, 1906), p. 199.

Source: King Lear

Introductio ad prudentiam: Part II (1727), Gnomologia (1732)

Source: Romeo and Juliet

The Complete Neurotic's Notebook (1981), Unclassified

Source: Don Quixote de la Mancha (1605–1615), Part I, Book IV, Ch. 4.

Plutarch's Life of Cato
Variant: Wise men profit more from fools than fools from wise men; for the wise men shun the mistakes of fools, but fools do not imitate the successes of the wise.

As quoted in One Big Fib : The Incredible Story of the Fraudulent First International Bank of Grenada (2003) by Owen Platt, p. 37