MTE5NDg0MDU0OTU2OTAxOTAzTo Charles Augustus Strong
Hotel Bristol
Rome. March 19, 1926

Do you suppose that there is any wonderful secret in Relativity, apart from mathematical calculations, which is beyond the understanding of the most willing mind? I doubt it: but of course we have to be silent until one of the Fach lets the cat out of the bag; it is the new system under which we live, the Soviet system, where a self-appointed committee of experts tell the world what it is expected to believe under pain of excommunication.

From The Letters of George Santayana:  Book Three, 1921-1927.  Cambridge, MA: The MIT Press, 2002.
Location of manuscript: Rockefeller Archive Center, Sleepy Hollow NY