The deeper the insight we obtain into the mysterious workings of nature's forces... the more we are convinced that we are still standing in the vestibule of science; that an unexplored world still lies before us; and however much we may discover, we know not whether mankind will ever arrive at a full knowledge of nature.

In: Gardner G. Hubbard, Annual Report of the Board of Regents of the Smithsonian Institution, 1891, The Evolution of Commerce (p. 660)