xri.] THE INDUCTIVE OK INVERSE METHOD. 269 



of the event, and then accepting the aggregate result as 

 the best which can be obtained. This solution is only to 

 be accepted in the absence of all better means, but like 

 other results of the calculus of probability, it comes to our 

 aid where knowledge is at an end and ignorance begins, 

 and it prevents us from over-estimating the knowledge we 

 possess. The general results of the solution are in accord- 

 ance with common sense, namely, that the more often an 

 event has happened the more probable, as a general rule, 

 is its subsequent recurrence. With the extension of 

 experience this probability increases, but at the same time 

 the probability is slight that events will long continue to 

 happen as they have previously happened. 



We have now pursued the theoiy of inductive inference, 

 as far as can be done with regard to simple logical or 

 numerical relations. The laws of nature deal with time 

 and space, which are infinitely divisible. As we passed 

 from pure logic to numerical logic, so we must now pass 

 from questions of discontinuous, to questions of continuous 

 quantity, encountering fresh considerations of much dif- 

 ficulty. Before, therefore, we consider how the great in- 

 ductions and generalisations of physical science illustrate 

 the views of inductive reasoning just explained, we must 

 break off for a time, and review the means which we 

 possess of measuring and comparing magnitudes of time, 

 space, mass, force, momentum, energy, and the various 

 manifestations of energy in motion, heat, electricity, 

 chemical change, and the other phenomena of nature. 



