Charles Maurice de Talleyrand-Périgord (a.k.a. Talleyrand) was a French diplomat of the late 18th Century.
A number of websites of quotes (for example: [1], [2], [3]) claim that he said:
"If we go on explaining we shall cease to understand one another."
I am usually very skeptical about such quote websites, even more since I have not found any other sources
Did he ever say that?