“A teacher affects eternity; he can never tell where his influence stops.”
~Henry Adams, American author & historian
The Education of Henry Adams (1918)* Boston, MA: Houghton Mifflin Company, 1918 edition, p. 300; online via Google Books, books.google.com
*Source note: Although Adams copied a few private editions of The Education of Henry Adams by 1907, the book was not published commercially until 1918.