500 LAPLACE. 



Laplace did not include the secular acceleration of the moon and 

 the theory of the tides in the list of his labours suggested by the 

 Theory of Probability. Also pages Li— LVL of the introduction 

 seem to have been introduced into the third edition, and taken 

 from the first supplement. 



Laplace does not give references in his Theorie...des Proh., so 

 we cannot say whether he published all the calculations respecting 

 probability which he intimates that he made; they would how- 

 ever, we may presume, be of the same kind as that relating to 

 the barometer which is given in page 350 of the Theorie...desFroh., 

 and so would involve no novelty of principle. 



Laplace alludes on page Liv. to some calculations relating to 

 the masses of Jupiter and Saturn; the calculations are given in 

 the first supplement. Laplace arrived at the result that it was 

 1000000 to 1 that the error in the estimation of the mass of 



Jupiter could not exceed — of the whole mass. Nevertheless it 



1 



has since been recognised that the error was as large as — ; see 



Poisson, Recherches sur la Proh..., page 816. 



9-iO. Laplace devotes a page to the Application dii Calcul 

 des Prohabilites aux Sciences morales; he makes here some inter- 

 esting remarks on the opposing tendencies to change and to con- 

 servatism. 



9-tl. The next section is entitled, De la Prohahilite des 

 temoignages; this section occupies pages Lxxi — Lxxxii : it is an 

 arithmetical reproduction of some of the algebraical investigations 

 of Chapter XL of the Theorie...des Proh. One of Laplace's discus- 

 sions has been criticised by John Stuart Mill in his Logic; see 

 Vol. 11. page 172 of the fifth edition. The subject is that to which 

 we have alluded in Art. 735. Laplace makes some observations 

 on miracles, and notices with disapprobation the language of 

 Racine, Pascal and Locke. He examines with some detail a 

 famous argument by Pascal which he introduces thus : 



Ici se presente naturellement la discussion d'un argument fameux 

 de Pascal, que Craig, mathematicieii anglais, a reproduit sous une forme 



