126 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



organs and states of mind. Such considerations serve to 

 show that the collection of data is hardly a preliminary 

 scientific technique, in the strict sense of the word. More 

 accurately, the accumulation and testing of data constitute 

 a task which is part and parcel of the scientific method it- 

 self. One does not start with data, for one never knows 

 whether his data are data until he has made a critical 

 analysis of them. And this very analysis involves an as- 

 sumption of many of the laws of science, which are them- 

 selves demonstrable only in terms of such data. In order 

 to assure oneself that he has normal conditions of observa- 

 tion he must use the laws of physiology and of psychology. 

 But these laws are themselves simply generalizations from 

 other data which are questionable upon similar grounds. 

 Hence, in order to ascertain the correctness of data one 

 must assume other data — which may themselves be in- 

 correct. This difficulty is unavoidable. 



When one has obtained his data through perception; 

 when he has increased them by operations performed upon 

 the end-objects and the physical media; when he has con- 

 trolled observation by attention to the possible disturbing 

 factors in the physiological media; finally, when he has dis- 

 cerned the various psychological factors, such as isolational, 

 symbolic, and inferential acts, he has completed the so- 

 called preliminary operations of science. What he gets 

 through this series of operations is a system of symbols 

 presumed to have the power of representing the data which 

 first called them into being. This system of symbols con- 

 stitutes a science. The next chapter will be devoted to an 

 examination of such an embryonic science. 



REFERENCES 



Morris Cohen, Reason and Nature (New York: Harcourt, Brace, 



1931), Chap. Ill, sects. I, II. 

 E. A. Burtt, Principles and Problems of Right Thinking (New 



York: Harper, 1928), Chap. V. 

 J. A. Creighton, Introductory Logic (New York: Macmillan, 1922), 



Chap. XIV. 



