104 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



increase. He soon recognizes that the task of science is 

 not merely getting the data, but increasing the variety and 

 scope of data by definable techniques. It is what man does 

 to nature that counts, for what nature tells him is a function 

 of his own exploratory operations. 



The descriptive techniques of modern science are many 

 and various. A detailed discussion of them would belong 

 properly in a laboratory manual rather than in a book on 

 scientific methodology. The details of the laboratory pro- 

 cedure will not, of course, be discussed here. The problem 

 is rather to consider these techniques only in their most 

 general features, and in so far as they have bearing on a 

 logic of science. 



For the purposes of rough classification one may divide 

 descriptive techniques on the basis of the contexts within 

 which they have major application. If the function of the 

 descriptive methods is to increase the range and variety 

 of data without introducing 'abnormal' appearances, a 

 discussion of such methods may conveniently follow the 

 analysis of the perceptual situation into its elements. Ac- 

 cordingly, descriptive techniques may be considered under 

 the following heads: (1) control of the end-object; (2) control 

 of the physical medium; (3) control of the sense organs; and 

 (4) control of the state of mind. 



CONTROL OF END-OBJECT 



A strictly descriptive science would be passive toward 

 nature. It would neither manipulate nor control, neither 

 move about nor transform objects. For on the presupposi- 

 tions of a purely positivistic approach to nature, the world 

 must be only what it obviously is; nothing conjectural or 

 doubtful can be included in science. But there is no science 

 which is purely and simply descriptive. The implication of 

 the study of nature is that objects are not only what they 

 are apart from man's intervention, but what they may be 

 made to become through his intervention. Objects are the 

 totality of their manifestations. Hence anything which one 



