INTRINSIC VALUE OF DIFFERENT NEW TRUTHS. 191 



those which produce the most immediate practical benefit, 

 but those which will ultimately explain, co-ordinate, and 

 include the greatest variety and number of facts. The 

 discovery of the law of action of gravity is generally con- 

 sidered by scientific philosophers to surpass all others in 

 importance, because of the great magnitude, variety, and 

 immense number of facts which it explains. Adopting 

 the above as a standard, we may reasonably conclude that 

 the discovery of a new force is intrinsically more important 

 than that of any law or mode of action of that force ; and 

 that of a new elementary substance is more important 

 than that of either of its compounds ; also that the dis- 

 covery of a general principle of structure or action of 

 material substances is of greater importance than that of 

 any solitary instance of it. Faraday made many dis- 

 coveries; but those of magneto-electric induction, the 

 relation of magnetism to light, and the universality of 

 magnetic action are considered the most important, 

 because they consist of general principles governing many 

 phenomena. 



The discovery of a new general relation between two 

 forces is very important : ' when we find out an idea by 

 whose intervention we discover the connection of two- 

 others, this is a revelation of God to us by the voice of 

 reason.' Newton, ' finding out intermediate ideas, that 

 showed the agreement or disagreement of the ideas, as 

 expressed in the propositions he demonstrated,' was ' led 

 into the truth and certainty of those propositions.' l 



The essential reason why the discovery of general 

 principles is of such relatively great importance is because 

 the fundamental facts and principles of a science implicitly 

 contain, in a latent state, all the minor truths which are 



1 Whewell, pp. 511, 512. 



