SCIENTIFIC DISCOVERY 191 



associated events become parts or aspects. The concretive 

 method is employed whenever diverse events are considered 

 to be explicable by the same complex entity, e.g., when ex- 

 pansion, surface tension, and solubility are presumed to be 

 explicable in terms of the molecular constitution of matter. 

 The definition of a substance as the totality of its properties 

 or manifestations is also a case of the concretive method, 

 i.e., it is an attempt to devise a construct in terms of which 

 it will be possible to understand the association of these 

 properties. Often the concretive method involves uniting 

 apparent incompatibles, as in the case of the supposition 

 that the ether is both a fluid and a solid, and in the hypoth- 

 esis that light is both wavelike and corpuscular. Frequently 

 the concretive method is concerned not with the supposition 

 of a complex entity, but merely with the postulation of a 

 more intimate correlation than that which is obviously 

 given. Inferences from some to all may be considered as 

 instances of the concretive method. 



Both of these methods, however, have been considered in 

 this connection merely as methods of construction, not as 

 methods of hypothesis. The method of abstraction attempts 

 to determine the properties of abstract features of events 

 on the basis of the events themselves, and the method of 

 concretion attempts to determine the properties of complex 

 events on the basis of what is known of the individual 

 events. But both abstractions and concretions, having 

 been defined by the method of construction, may be in- 

 creased by the method of hypothesis. Through this method 

 the meanings of the abstractions and concretions are in- 

 creased in such a way as to permit the deduction of further 

 descriptive propositions. For example, measured values 

 take on all of the features of the mathematical systems of 

 which they are parts, and, as a result, the quantities which 

 are measured by means of them take on additional properties. 

 In the same way, the notion of molecules is enlarged through 

 imaginative activities, and, as a result, new properties de- 

 scriptive of the behavior of bodies are predictable. Such 



