CONCLUDING REMARKS. 179 



ledge of any particular science developes itself, our views of 

 it become more simple ; hypotheses, or the introduction of 

 supposititious views, are more and more dispensed with ; 

 words become applicable more directly to the phenomena, 

 and, losing the hypothetic meaning which they necessarily 

 possessed at their reception, acquire a secondary sense, which 

 brings more immediately to our minds the facts of which they 

 are indices. The scaffolding has served its purpose. The 

 hypothesis fades away, and a theory, or generalised view of 

 phenomena, more independent of supposition, but still full of 

 gaps and difficulties, takes its place. This in its turn, should 

 the science continue to progress, either gives place to a more 

 simple and wider generalisation, or becomes, by the removal 

 of objections, established as what is termed a law. Even in 

 this more advanced stage words importing theory must be 

 used, but phenomena are now intelligible and connected, 

 though expressed by varied forms of speech. 



To think on nature is to theorise ; and difficult it is not to 

 be led on by the continuities of natural phenomena to theories 

 which appear forced and unintelligible to those who have not 

 pursued the same path of thought ; which, moreover, if allowed 

 to gain an undue influence, seduce us from that truth which 

 is the sole object of our pursuit. 



Where to draw the line where to say thus far we may 

 go, and no farther, in any particular class of analogies or rela- 

 tions which Nature presents to us ; how far to follow the 

 progressive indications of thought, and where to resist its 

 allurements, is a question of degree which must depend upon 

 the judgment of each individual or of each class of thinkers ; 

 yet it is consolatory that thought is seldom expended in vain. 



I have throughout endeavoured to discard the hypotheses 

 of subtle or occult entities ; if in this endeavour some of my 

 views have been adopted upon insufficient data, I still hope 

 that this Essay will not prove valueless. 



The conviction that the so-called imponderables are modes 

 of motion, will, at all events, lead the observer of natural 

 phenomena to look for changes in these affections, wherever 

 the intimate structure of matter is changed ; and, conversely, 

 to seek for changes in matter, either temporary or permanent, 



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