material wealth, and between productive and unproductive services, and to regard as “industrial” all processes which conduce to the production of anything that is bought and sold, it is impossible to form clear judgments about the industrial prosperity of a nation and the part which external trade plays in it.
§3. The reason for this insistence becomes evident when we regard the development of needs and satisfactions which mark the history of a progressive nation. In earlier stages of industrial development, progress will consist primarily in the increase of the quantity and variety of material goods for the satisfaction of simple physical wants. Most of the industrial energy of a population in an early stage will go into the extractive arts of agriculture and of certain simple modes of manufacture; a little later on mining will play a considerable part as an extractive industry, and the modes of manufacture will be more numerous and complex. As industrial civilisation advances under the pressure of expanding needs, a smaller proportion of energy will be devoted to the extractive arts and the primary manufactures, a larger proportion to the more complex industrial processes adapting raw materials or crude manufactures to the more special needs of various classes of consumers. A very rapid increase of population may delay this process by keeping a large proportion of energy employed in raising food; a very rapid
