52 GENERAL VIEW AND BASIS OF SCIENTIFIC RESEARCH. 



mental one. By further action of the mind, the idea of 

 existence becomes stronger, and is often accompanied by 

 a conception of its relative magnitude to other ideas. As 

 soon as we begin to think, we begin to compare. 



The implicit contents of different scientific ideas differ 

 not only in kind, but vary greatly in amount. As the 

 extension of an idea, or the number of objects it represents, 

 increases, so the quantity of knowledge implied in it in- 

 creases also. As likewise, the intension of an idea, or the 

 number of marks or attributes it includes, increases, so 

 also does the quantity of implied knowledge. The quan- 

 tification of ideas (and terms) is a very abstruse subject, 

 greatly requiring development, and is important in pro- 

 portion to its abstruseness. That ideas of simple existence, 

 when clearly conceived, possess relative degrees of magni- 

 tude, is shown in the processes of analysis, division and 

 classification of knowledge, and in logical inference. 

 Nearly every single idea, considered either in extension or 

 intension, is more or less complex, and may be analysed, 

 divided, and subdivided into its component parts, or ideas 

 of more and more limited meaning, and therefore con- 

 taining less and less knowledge. In drawing a logical 

 inference also, we must be careful that it does not contain 

 a larger idea than the one contained in the original pro- 

 position. 



Although, for the purposes of scientific discovery, it is 

 necessary to classify ideas in every possible way in order 

 to extract from them the maximum amount of knowledge, 

 and for special purposes it is necessary to classify them in 

 special ways, yet it is equally necessary in a systematic 

 representation of knowledge, and in all cases where we 

 wish to determine the relative degrees of intrinsic value 

 or importance of things, to classify them upon the most 

 fundamental basis we can find. Viewed in this aspect, 





