178 LIGHT SCIENCE FOR LEISURE HOURS. 



tions. It will be found that this method of viewing 

 matters is never expressed except by persons who have 

 fallen into the habit of accumulating observations 

 without reasoning upon them in fact, without utilis- 

 ing them. Observation is with them not a means but 

 an end. It seems to me, or rather I may speak more 

 confidently and say that the whole history of science 

 proves, that the real value of observation and experiment 

 lies not in themselves, but in what may be deduced 

 from them. They are the raw material whence 

 scientific knowledge is to be manufactured. It is not 

 the object of a theory to afford a convenient means of 

 classifying observations and also to suggest occasion 

 for making them, but to educe their real significance ; 

 and the sole reasonable object of observations is to 

 suggest the true theory and to afford the means of 

 testing and rejecting false ones. To assert that it 

 matters little what theory is suggested so long as it 

 affords a convenient means of classifying observations, 

 is as absurd in reality as it would be to assert that it 

 matters very little in what manufacture raw materials 

 of a particular kind are employed, so that the manu- 

 facture affords a ready means of sorting them away and 

 making room for fresh stores of them. The object of 

 manufacture is to make articles which shall have real 

 value, and raw materials are only of use in so far as 

 they can be employed in the manufacture of articles 

 of such a nature. In like manner the object of 

 theorising or reasoning is to discover actual truths, 

 and observations are only useful in so far as they 



