XL] PHILOSOPHY OF INDUCTIVE INFERENCE. 239 



Inductive inference might attain to certainty if our 

 knowledge of the agents existing throughout the universe 

 were complete, and if we were at the same time certain 

 that the same Power which created the universe would 

 allow it to proceed without arbitrary change. There is 

 always a possibility of causes being in existence without 

 our knowledge, and these may at any moment produce 

 an unexpected effect. Even when by the theory of pro- 

 babilities we succeed in forming some notion of the com- 

 parative confidence with which we should receive in- 

 ductive results, it yet appears to me that we must make 

 an assumption. Events come out like balls from the vast 

 ballot-box of nature, and close observation will enable us 

 to form some notion, as we shall see in the next chapter, 

 of the contents of that ballot-box. But we must still 

 assume that, between the time of an observation and that 

 to which our inferences relate, no change in the ballot-box 

 has been made. 



