SOURCES OF KNOWLEDGE. 33 



ledge ; but, we cannot think ourselves into an acquaint- 

 ance with even the simplest thing that we do not know by 

 some other means. It is the belief that we can ; that 

 thought will do what thought never did, can do, or 

 was intended to do, which lies as a stumbling-block 

 in our path, and hinders us from knowing a great 

 many things that would be very useful as well as 

 very pleasant to us. 



Then, how do we come by our knowledge ? A 

 simple case will show that better than many words 

 about it: It is a lovely summer morning, the sun 

 shines brightly, the air is perfumed by the scent of 

 the roses ; and the songs of the birds are very de- 

 lightful music. Be it so. How do we know that 

 the sun shines ? " We see it with our eyes.*' Very 

 true : we see the light, and we see the sun ; and as 

 we never see that kind of light without seeing the 

 sun, and never see the sun without seeing that kind 

 of light, we in our thoughts associate the two to- 

 gether, and can no more help saying that the sun 

 shines than we can doubt that we see it. 



But how do we know as regards the perfume of 

 the roses ? " We smell it :" and as we have never 

 seen the flowers which we call roses without smell- 

 ing what we call the perfume of roses ; and never, 

 unless We be able to account for it in some other 

 way (as by the exposure of rose-water or oil of roses 

 to the atmosphere), smell that perfume except where 

 roses were near us, whether within our sight or not, 

 we have learned by the judgment of our minds to 

 associate the smell with the flowers ; and can no 

 more refrain from thinking it the smell of roses, than 

 we can from perceiving the perfume. 



In the case of the songs of the birds, there is an- 

 other organ affected, but the process is the same : 

 the ear never hears such sounds unless there are 

 birds in the case, or some substitute for birds, which 

 is explainable in some other way ; and, therefore, 



