The powers which such individuals exercise are real and effective. But we 

 too often forget that these powers do not properly belong to the individuals 

 who push buttons or make the special marks on paper. These powers have been 

 brought together by hundreds of persons, from widely separated areas, and 

 stored in the comparatively small machines which particular individuals 

 operate. No scientist or engineer could, by himself, either make or use such 

 powerful devices — a telephone system, for example, or a printing press, or a 

 textile mill. Nor could any individual — by himself — use such powers. The 

 press is useful only because hundreds of persons are interested in reading the 

 same book or paper. The telephone is useful only if thousands of people, 

 scattered over a large territory, are interested in communicating with each 

 other. If you had a whole factory to work or play with — by yourself — it 

 would not add much to your control over your environment. 



Any person standing at a switch and making one train go along one track 

 and the next along another track may get the notion that he is doing it all 

 himself. Many individuals do in actual Hfe control power in much that way. 

 And they grow into the conceit that it is theirs to do with as they like. But 

 it is our power. It will continue to grow, and it will continue to serve man- 

 kind, only as we are satisfied to use it for common purposes, rather than for 

 the benefit of the individual who happens to be standing at the switch, or at 

 the traffic signal. 



Human power has grown by increasing numberless special skills and special 

 devices which are of use to those who have them only because others need them. 

 A doctor cannot make a living by using his medical knowledge on his own body 

 or on his family. A cotton-grower cannot Hve on cotton, nor the tanner on 

 his product. The power which comes from division of labor and exchange of 

 services is socially created power — that is, power created by people living to- 

 gether. And the power can benefit human beings only as it is put to work 

 through co-ordinated and co-operative effort; only socially is it usable. 



Interdependence The advancement of science has been accompanied 

 by a rapid growth of cities in population and wealth. These changes have 

 been so striking that many of us have assumed that by sending everybody 

 into the city we can assure abundance for everybody. The appearance, how- 

 ever, is misleading. In a city like New York or Chicago several thousand 

 persons can indeed live on a square mile of land, but only because our division 

 of labor and our highly perfected means of transportation and communication 

 enable us to bring them the organic materials essential for life. 



Under the best agricultural practices it would take thousands of acres and 

 thousands of rural workers and transportation workers to supply food to even 

 a small city. In a state like Connecticut or in a country like England the popu- 

 lation can continue to live only so long as vast quantities of fresh and preserved 

 foods continue to be brought in from distant points. The people living in 



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