280 Probability before and after the event. [CHAP. xn. 



relatively, future, for in that case direct information concern 

 ing the contemplated result being impossible, all persons are 

 on precisely the same footing of comparative ignorance, and 

 must form their opinion entirely from the known or inferred 

 frequency of occurrence of the event in question. On the 

 other hand, if the event be passed, there is almost always evi 

 dence of some kind and of some value, however slight, to 

 inform us what the event really was ; if this evidence is not 

 actually at hand, we can generally, by waiting a little, obtain 

 something that shall be at least of some use to us in forming 

 our opinion. Practically therefore we generally confine our 

 selves, in anticipations of this kind, to what is really future, 

 and so in popular estimation futurity becomes indissolubly 

 associated with probability. 



3. There is however an error closely connected with 

 the above view of the subject, or at least an inaccuracy of 

 expression which is constantly liable to lead to error, which 

 has found wide acceptance, and has been sanctioned by 

 writers of the greatest authority. For instance, both Butler, 

 in his Analogy, and Mill, have drawn attention, under one 

 form of expression or another, to the distinction between im 

 probability before the event and improbability after the 

 event, which they consider to be perfectly different things. 

 That this phraseology indicates a distinction of importance 

 cannot be denied, but it seems to me that the language in 

 which it is often expressed requires to be amended. 



Butler s remarks on this subject occur in his Analogy, in 

 the chapter on miracles. Admitting that there is a strong 

 presumption against miracles (his equivalent for the ordi 

 nary expression, an improbability before the event ) he 

 strives to obtain assent for them by showing that other 

 events, which also have a strong presumption against them, 

 are received on what is in reality very slight evidence. He 



