156 not necessarily imply complete rule, and to subdue does not necessarily mean to destroy. Others have written ably on the subject of the changing relationship of man to his environment, of his development from hunter to herdsman, from gatherer to cultivator, from a user of shaped rocks and simple tools to a maker of computers, from a thrower of stones to 12 a dropper of giant bombs. History is replete with examples of how man has shaped and organized nature to his own ends. Through migration and conflict he has filled a seemingly boundless earth and through organ ization, effort, and strength of will, exploited it. For a time and in a few places, production came to represent a worthwhile and achievable end in itself; and a second thought followed close on the heels of the first: that increasing levels of consumption might represent an even more desirable, and apparently just as possible end. The twin ideas of increasing production and consumption, reflected in modern income accounting terms as continued increases in national product, came and therefore will be taken, but the range of rational alternative actions is limited by the environment. Eskimos do not grow bananas, nor is coal mined where there is no coal. 12 See especially a series of articles by Carl Sauer, Clarence Glacken, Alexander Spoehr, and Pierre Teilhard de Chardin in Mans Role in Changing the Face of the Earth, ed. by Thomas, op. cit..