THE PRINCIPLES OF SCIENCE 189 



by filling interplanetary space with a "field." This endeavor, as Sam- 

 bursky observes, reaches its supreme expression in Einstein's general 

 theory of relativity, where 



... a physical point is simply a singularity in the "metric field" 

 which surrounds it. Again, this field is not at all an empty space, 

 but a kind of emanation of the matter in it, just as matter is a kind of 

 "materialization" of the field. 



At the very opposite end of the scale of magnitudes, we find in 

 modern microphysics an entirely analogous reduction of what once 

 appeared an absolute dichotomy. To the discrete corpuscular "elec- 

 tron" of the 19th century we now impute also some of the character- 

 istics of a continuous wave and, conversely, to the purely undulatory 

 "light" of the 19th century we now impute some of the properties of 

 a corpuscle. Again there is a marriage of continuity and discontinuity 

 and, though quantum mechanics has so far provided only a shotgun 

 wedding, the union has been fruitful and enduring. 



DISSOLUBILITY AND SUPERPOSITION 



Superposability, the possibility of reconstituting wholes from parts, I 

 regard as corollary to the principle of continuity. Dissolubility, the 

 separability of parts from wholes, is taken as a principle even by 

 common sense. Already examined from various aspects in Chapters 

 II, III, and V, the principle of dissolubility was seen in Chapter VI as 

 the keystone of all experiment. The immense power attainable by 

 work with artificial controlled systems becomes ours only as we 

 bring that principle to bear to isolate and subdivide our problems. 

 Quite recently we first learned that at the microcosmic level the 

 "part" we can hope to isolate is not an event as such, but only the 

 unit of event and apparatus required to render it as some observable 

 large-scale eflFect. Aside from this minor qualification, however, 

 quantum mechanics leaves untouched our habitual exploitation of 

 dissolubility in the design of experiments. 



In thought we proceed exactly as we do in experiment. Beginning 

 with concepts of discrete objects and distinct phenomena, we resolve 

 the world into "parts" we consider in abstraction from the whole. By 

 way of superposition of these more comprehensible parts, we seek 

 the whole that is often conceptually inaccessible in itself. But the 

 superposability this program confidently assumes may well fail to 



