whether the basis of classification is the nature of the problem and 

 solution or the method of procedure employed in deriving the theory. 

 From the point of view of the nature of problem and solution, we 

 have found that there is one class of theories whose problem is to 

 explain the process of origin and a second class whose problem is to 

 reveal the essential nature of a thing. From the point of view of 

 method of solution, we found that there were also two classes: those 

 which proceed by observation and experiment, a sub-class of which 

 makes use of assumptions in completing an evidential chain; and 

 those which proceed by making assumptions and developing the 

 logical implications of those assumptions. 



A further examination of the theories shows that either method 

 of procedure might be used with either class of problem. Darwin's 

 problem is one of origin and his method is that of observation and 

 experiment; while Hyslop's problem is also one of origin but his 

 method that of assumption and deduction. On the other hand, the 

 problem in the theory that matter is electrical is one of definition and 

 the procedure in solving it is that of observation, and experiment. 

 While Locke's problem in his theory of knowledge is also one of 

 definition but his method is That of assumption and deduction. It 

 is evident from this that whether the problem is one of origin or one 

 of definition, the method of procedure in solving it may be either 

 experimentation or assumption and deduction. 



Having in this chapter classified the theories, and compared their 

 problems and methods of procedure and discussed the relation exist- 

 ing between the two, we shall continue our study by an examination 

 of the qualities of theories. 



13] 



