George Sewall Boutwell, Reminiscences of Sixty Years in Public Affairs… (1902)
“ Professor Guyot taught physical geography, and previous to 1855 he had wrought a change in public opinion in regard to the method of introducing the science to children. All the then recent text-books omitted physical geography, or reserved it for a brief chapter at the close of the work. Guyot changed the course of study. His motto was this: “We must first consider this earth as one grand individual.” ”
