106 INTRODUCTION TO PHILOSOPHY OF SCIENCE 



been neutral." * Similar difficulties of a more significant 

 character are revealed by the Heisenberg principle of in- 

 determinacy. In the case of the observation of small 

 particles the method of observation, e.g., the use of a light 

 wave, may influence their states in such a way that one 

 cannot assign to them with a high degree of precision both 

 location and velocity. It seems likely that as science ad- 

 vances there may be disclosed an increasing dependence of 

 the end-object upon all kinds of environmental changes, 

 including the introduction of instruments and other recording 

 devices. 



A complete listing of the operations which may be per- 

 formed upon objects would be impossible. Characteristic 

 among them are analyzing and synthesizing, speeding and 

 slowing, intensifying and diminishing, melting, burning, so- 

 lidifying, dissolving, boiling, condensing, pulverizing, re- 

 shaping, magnetizing, stretching, compressing, dyeing, de- 

 composing, and ionizing. All of these may be said, in some 

 sense, to introduce changes in the object — changes which 

 are in some cases reversible and in some cases not. In each 

 case the aim is to bring about a new manifestation or ap- 

 pearance of the object, but by doing something to the object 

 itself rather than merely to the physical medium. 



An interesting feature of this type of technique is that it 

 tells the observer not what objects are but what they were. 

 It defines objects not in terms of their actual characters 

 but in terms of their potentialities. It identifies objects 

 only by destroying them in the very act of identification. 

 Though such a method does give the observer information 

 about objects, this knowledge is of the kind which Edding- 

 ton 2 calls "retrospective inference." The presumption in 

 each case is that the objects in question are defined not 

 merely in terms of retrospective inference but exhibit some 

 properties which can be directly observed, and hence permit 

 knowledge of the present rather than merely of the past. 

 Clearly if one's knowledge of objects were obtained only 



1 H. Levy, Universe of Science, p. 66. 2 New Pathways in Science, p. 93. 



