The life a mountaineer who never saw the sea is different from the life of a sailor who never saw a mountain. People of the Sahara desert, which has an annual rainfall of less than 10 inches, act and think differently from people of Malaya, which has an annual rainfall of more than 10 inches. Men who raise corn on the plains of Illinois differ in many ways from men who dig copper in the mines of Arizona. Physical environment means more to the lives of men than a mere stage on which to play the drama of life.