CHAPTER III. 



NEW TRUTH, AND ITS GENERAL RELATION 

 TO HUMAN PROGRESS. 



THE great source of the success of applying science 

 to trade, and of the beneficent effect of science upon 

 human welfare in general, is simply the influence of 

 demonstrable truth. We know that if we have once 

 discovered all the principles, laws, and conditions of 

 some scientific phenomenon, or of some improved 

 process or result in a manufacture, the reproduction 

 of exactly the same conditions will hereafter enable 

 us to invariably produce the same result. In this 

 respect science differs from dogma, the truth or falsity 

 of which cannot be demonstrated ; it also differs from 

 empiricism, because when empirically working a pro- 

 cess we are ignorant of the principles or laws which 

 are operating, whilst with a scientific knowledge we 

 understand those laws, and can direct them to our 

 particular purposes. In the process of electro-plating 

 for example, we understand the laws of the phenom- 

 ena, and can direct them so as to obtain silver of a 

 hard or soft quality, brittle or tough, crystalline 

 silver, &c., according to our wish ; but if we had only 

 an empirical knowledge of the subject we could not 

 thus vary the process. 



