PHILOSOPHY OF SCIENCE 23 



levels, and the question of importance depends upon the 

 level in which one is interested. Thus out of the attempt to 

 integrate the two fields there arose a study whose problem 

 was precisely the integration of the two fields, and this 

 gradually became the discipline which is now called "the 

 philosophy of science." 



The second factor responsible for the emergence of the 

 philosophy of science was the appearance in science itself of 

 certain features which were responsible for its own instabil- 

 ity. The philosophy of science is inevitable whenever a 

 science becomes self-critical. But self-criticism arises only 

 when there is an obvious breakdown. So long as a machine 

 operates smoothly there is no occasion for the operator to 

 suspect that it is not in order. The smooth operation seems 

 a sufficient guarantee of efficiency and adequacy. But now 

 suppose the machine suddenly to stop, either because of 

 an internal breakdown or because of an external obstacle. 

 Immediately the question arises as to the cause of the inter- 

 ruption, and more specifically, as to the general character 

 of a machine which will suddenly stop in the face of a prom- 

 ise of continued functioning. A breakdown can never occur 

 unless it is potentially in the engine even when it appears 

 to be running smoothly. And an engine which has the 

 potentiality of breaking down is clearly an inferior engine, 

 as compared with one which has not this potentiality. 

 Thus the problem of preventing malfunctioning is as much 

 a problem in connection with machines as is the problem of 

 guaranteeing continued functioning. Now if the subject 

 matter of one's study is not an engine but science itself, the 

 problem is essentially the same. Science belongs to science 

 so long as it exhibits no inadequacies. But when science 

 proves inadequate it belongs to philosophy. This does not 

 mean that philosophy functions as the great intellectual 

 repair man. Mere repairing is essentially the same problem 

 as original construction, namely, a scientific problem. Phi- 

 losophy repairs only in the sense that it attempts to show 

 primary inadequacies, unwarranted original assumptions, 



