EDWARD S. MASON 179 



Foundation is moved to inquire whether man is a "biological cancer." 

 Mankind has earlier been characterized as a "disease of the dust" and 

 the disease seems to be spreading rapidly. If we take such calculations 

 seriously there is little need to talk about conservation. We might as 

 well consume what we have now since our descendants are going to 

 starve in any case. 



There is, however, another school of thought that finds unlimitedly 

 optimistic conclusions in the effects on resource availabilities of con- 

 tinuous advance in science and technology. The de-salting of sea water 

 can cause the deserts to bloom; there are vast untapped mineral re- 

 sources in low-grade ores and in the sea; and, if this planet gets a 

 trifle congested, the space ships of the future will be available to 

 remove the surplus to other worlds. If this is the preferred vision, it 

 leads equally to the conclusion, but for opposite reasons, that there is 

 little need to worry about the future. 



Perhaps because I am merely a pedestrian economist these alterna- 

 tive visions of the future do not greatly stir me. There is really no 

 need to assume that population will increase indefinitely at exponen- 

 tial rates since human institutions and values have shown in the past, 

 and will undoubtedly exhibit in the future, some capacity for adapta- 

 tion to changing situations. And while science and technology are 

 wonderful, they show no signs as yet of exorcising the persistent fact 

 of scarcity. To undertake a serious discussion of conservation the 

 period of time under consideration has to be limited to that within 

 which one can perceive, at least dimly, the approximate magnitude of 

 the relevant variables. 



A consideration of these variables does well to distinguish between 

 conservation applied to particular raw materials and conservation as 

 it relates to broad resource categories such as land and water. Of basic 

 importance to a consideration of particular materials is the high de- 

 gree of substitutability among both mineral and agricultural products. 

 Agricultural land and, to a less extent, water resources, exhibit, more- 

 over, a great capacity for adaptation to different uses. Our minerals 

 resource base is, of course, much more highly specialized. Although 

 there is large substitutability among groups of mineral products, e.g., 

 ferro alloys, it is difficult to extract copper from an iron ore deposit. 

 The over-all limiting factor to minerals output would appear to be 



