GROUNDS OF DISBELIEF. 175 



as likely to have been really thrown as the other series. If, 

 therefore, this assertion is less credible than the other, the 

 reason must be, not that it is less likely than the other to be 

 made truly, but that it is more likely than the other to be 

 made falsely. 



One reason obviously presents itself why what is called a 

 coincidence, should be oftener asserted falsely than an ordi 

 nary combination. It excites wonder. It gratifies the love of 

 the marvellous. The motives, therefore, to falsehood, one of 

 the most frequent of which is the desire to astonish, operate 

 more strongly in favour of this kind of assertion than of the 

 other kind. Thus far there is evidently more reason for dis 

 crediting an alleged coincidence, than a statement in itself 

 not more probable, but which if made would not be thought 

 remarkable. There are cases, however, in which the pre 

 sumption on this ground would be the other way. There are 

 some witnesses who, the more extraordinary an occurrence 

 might appear, would be the more anxious to verify it by the 

 utmost carefulness of observation before they would venture 

 to believe it, and still more before they would assert it to 

 others. 



6. Independently, however, of any peculiar chances of 

 mendacity arising from the nature of the assertion, Laplace 

 contends, that merely on the general ground of the fallibility 

 of testimony, a coincidence is not credible on the same amount 

 of testimony on which we should be warranted in believing an 

 ordinary combination of events. In order to do justice to his 

 argument, it is necessary to illustrate it by the example chosen 

 by himself. 



If, says Laplace, there were one thousand tickets in a box, 

 and one only has been drawn out, then if an eye-witness affirms 

 that the number drawn was 79, this, though the chances were 

 999 in 1000 against it, is not on that account the less 

 credible ; its credibility is equal to the antecedent probability 

 of the witness s veracity. But if there were in the box 999 

 black balls and only one white, and the witness affirms that 

 the white ball was drawn, the case according to Laplace is very 



