129 



night it was no longer a theory to him, but it was so for many years 

 afterwards to the world, and why? Because he could not get 

 cylinders made which did not leak, and pistons whicli were air- 

 tight, — in short, because of the "inability of practice to imitate the 

 model theory set before it." 



The third aspect of the question is the one which has received 

 most attention, by all except men of science. In this case, there 

 are two rival means, — one known by experience to be sufficient for 

 the end, the other as a rule discovered by the philosopher in his 

 study, or the chemist in his laboratory, and shown by a process of 

 reasoning to be capable of producing the end more efficaciously or 

 more profitably than the old means. The successive steps are the 

 same in all the three cases. First, there is knowledge, then a 

 proposal to employ the knowledge as a means to an end — that is 

 to apply it to some practical purpose, — and lastly, there is the active 

 process towards the end. But in new cases there is always an 

 element of uncertainty as to whether the end will be successfully 

 attained, and, until this uncertainty is rem'oved, the proposed means 

 is generally known by the name of theory. In the two former 

 aspects there is only one means to one end, and though there may 

 be the same, if not greater, interests at stake, there is not, as a rulej 

 the same antagonism of interests, and, consequently, not the same 

 amount of discussion. When there are two means, it invariably 

 happens that one is regarded as infallible ; it is knowTi from 

 experience that it has only to be applied and the desired end wiU 

 inevitably folloAv ; the other is looked upon with suspicion, and the 

 men who propose to apply it, and those who first actually apply it 

 to tlie requirements of life, are by some called theorists. These 

 so-called theorists may sometimes be too persistent in pushing a 

 theory after it has had abundance of trial ; or they may be too 

 imiiatient, and throw up a theory before it has been sufficiently 

 tried. There are examples of both kinds of men, and to such is 

 due the disrepute into which theory has fallen ; but without such 

 theorists at all, practice would be stationary. And who are the 

 practical men I Those who profess to be guided only by the 

 experience they gain in the pursuit of their several branches of 



