A long time ago, I posted a collection of quotes, all of them expressing the same idea: If I Had More Time, I Would Have Written a Shorter Letter.

Today, I discovered a detailed article by Quote Investigator concerning those who have expressed this excellent idea.

The conclusion:

[T]he number of different people credited with this comment is so numerous that an explanatory appendix would have been required, and the letter was already too long. Here is a partial list of attributions I have seen: Mark Twain, George Bernard Shaw, Voltaire, Blaise Pascal, Johann Wolfgang von Goethe, Winston Churchill, Pliny the Younger, Cato, Cicero, Bill Clinton, and Benjamin Franklin. Did anybody in this group really say it? . . .

In conclusion, Blaise Pascal wrote a version of this saying in French and it quickly moved into the English language. The notion was very popular and variants of the expression have been employed by other notable figures in history. The saying has also been assigned to some prominent individuals without adequate factual support.