174 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



occurs. But the data thus discovered might have remained 

 unknown had it not been for the directed attention; hence 

 their discovery is a result of the theoretical activity of the 

 scientist. For this reason the real problem in this connection 

 centers about the discovery of the hypothetical and theoret- 

 ical notions which are to serve as the guiding factors in 

 observation. The mystery in science is not how one dis- 

 covers facts which are obvious, but how one discovers 

 theories which in turn enable him to discover facts which 

 are not obvious. 



In the second place, for the descriptive view of science 

 there is no problem of scientific discovery. Hence the in- 

 troduction of this chapter into the discussion implies that 

 science is not merely positivistic. The reason for this can be 

 seen in the considerations of the preceding chapter. For 

 strict positivism science does not anticipate nature through 

 imaginative devices; instead it merely records and classifies 

 what is directly given. For modified positivism science does 

 anticipate nature through such techniques, though it looks 

 upon them merely as working instruments. For realism 

 science definitely posits entities "behind' the data in terms 

 of which the latter are to be explained and through which 

 they are to be supplemented. Now it is, perhaps, a more or 

 less arbitrary question as to just where in this continuum 

 explanation enters; the positivists deny that they explain, 

 the realists insist that they explain, the modified positivists 

 maintain that they explain only in a carefully specifiable 

 sense. But it is clear that the admission of significant acts of 

 mind — be they concerned with the formation of constructs, 

 conventions, or language — involves more than mere classifi- 

 cation and correlation of data. Hence a recognition of the 

 presence of acts of mind, i.e., movements of scientific dis- 

 covery, is equivalent to the admission that science is more 

 than descriptive. 



In the third place, the formulation of the problem in terms 

 of discovery rather than invention should not be taken as 

 prejudicial to the positivism-realism controversy. As was 



