George Bernard Shaw (1856-1950), Major Barbara (New York: Brentano’s, 1917; premiered 1905), p. 67.
CUSINS. Let me advise you to study Greek, Mr. Undershaft. Greek scholars are privileged men. Few of them know Greek; and none of them know anything else; but their position is unchallengeable. Other languages are the qualifications of waiters and commercial travellers: Greek is to a man of position what the hallmark is to silver.