“They wonder much to hear that gold, which in itself is so useless a thing, should be everywhere so much esteemed, that even men for whom it was made, and by whom it has its value, should yet be thought of less value than it is.”

Source: De architectura (The Ten Books On Architecture) (~ 15BC), Book I, Chapter I, Sec. 16
Context: As for men upon whom nature has bestowed so much ingenuity, acuteness, and memory that they are able to have a thorough knowledge of geometry, astronomy, music, and the other arts, they go beyond the functions of architects and become pure mathematicians. Hence they can readily take up positions against those arts because many are the artistic weapons with which they are armed. Such men, however, are rarely found, but there have been such at times; for example, Aristarchus of Samos, Philolaus, and Archytas of Tarentum, Apollonius of Perga, Eratosthenes of Cyrene, and among Syracusans Archimedes and Scopinas, who through mathematics and natural philosophy discovered, expounded, and left to posterity many things in connection with mechanics and with sundials.

Zwingli Opera, Corpus Reformatorum, Volume 1, p. 427-428.

Spending to Save: The Complete Story of Relief (1936), p. 184

Part III, Chapter X, The Status of Gold and Silver, p. 127
Storage and Stability (1937)

Source: City (1952), Chapter 7, “Aesop” (p. 201)

Advice to Clever Children (1981)

O’Connell’s Correspondence, Letter No 700, Vol II