1895-1990 1899-1979 1907-1977 20thcentury 500 allen americanliterature anthropologists civilization eiseley evolution(biology) history historyandcriticism humanecology humanevolution knowledge lewis literatureandtechnology naturalhistory naturalists nature philosophy science socialaspects socialevolution technology technologyandcivilization technologyandcivilizationinliterature technologyeiseley technologytate unitedstates viewsontechnologyandcivilizationmumford