6 Dynamic Evolution 



"law" should not be overlooked. When sci- 

 entists find heterogeneous results, the causes 

 of which are unknown, they formulate general 

 statements which represent the most common 

 results but which are subject to many excep- 

 tions. Such a statement represents a rule. 

 When they reach causes and learn how those 

 causes operate to produce the observed re- 

 sults, they formulate statements of laws which 

 cover all possible results. That a given law 

 operating in a uniform manner will appear 

 to the uninformed to produce contradictory 

 results, is a well-known fact. Thus, gravita- 

 tion attracts bodies toward the center of the 

 earth, yet a balloon rises, and it does so under 

 the uniform action of gravitation. Similarly, 

 the apparently contradictory results of breed- 

 ing operations in animals may be shown to be 

 due to the same law operating all of the time 

 in the same way. The apparent contradic- 

 tions are understood when the intervening 

 causes have been determined and measured. 

 The mass or quantity of matter in a body 

 is the product of its Volume and Density. 



