In 1956 in an international symposium at Princeton on the theme Man's role in changing the face of the Earth, one of the principal contributors, Carl Sauer, reflected that as much as anything it was a festival of remembrance to George Perkins Marsh. Marsh was perhaps the inspiration for viewing man within his natural world, within his ecological setting, but a setting which had evolved as much as anything by the actions of his own hand as it had been by natural agents. Marsh's great work Man and Nature, has been dubbed ‘the fountainhead of the conservation movement.’ Thus Sauer suggests that this study is based on man's: