48 ARBUTHXOT. 



as he expresses it in another place, in bringing to perfection the 

 art of arts, which is the art of thinking. 



See Leihnitii Opera Omnia, ed. Dutens, Vol. v. pages 17, 22, 28, 

 29, 203, 206. Vol. Vi. part 1, 271, 304. Erdmann, page 175. 



See also Opera Omnia, ed. Dutens, Vol. vi. part 1, page 36, 

 for the design which Leibnitz entertained of writing a work on 

 estimating the probability of conclusions obtained by arguments. 



77. Leibnitz however furnishes an example of the liability to 

 error which seems peculiarly characteristic of our subject. He 

 says. Opera Omnia, ed. Dutens, Vol. vi. part 1, page 217, 



...par exemple, avec deux des, il est aussi faisable de jetter douze 

 points, que d'en jetter onze ; car Tun et I'autre no se peut faire que 

 d'une seule manierej mais il est trois fois plus faisable d'en jetter 

 sept; car cela se peut faire en jettant six et un, cinq et deux, quatre 

 et trois; et une combinaison ici est aussi faisable que I'autre. 



It is true that eleven can only be made up of six and five ; but 

 the six may be on either of the dice and the five on the other, so 

 that the chance of throwing eleven with two dice is twice as great 

 as the chance of throwing twelve : and similarly the chance of 

 throwing seven is six times as great as the chance of throwing 

 twelve. 



78. A work entitled Of the Laws of Chance is said by Montu- 

 cla to have appeared at London in 1692; he adds mais n'ayant 

 jamais rencontr^ ce livre, je ne puis en dire davantage. Je le 

 soupconne n^anmoins de Benjamin Motte, depuis secretaire de 

 la society royale. Montucla, page 391. 



Lubbock and Drink water say respecting it, page 43, 

 This essay, which was edited, and is generally supposed to have 

 been written by Motte, the secretary of the Koyal Society, contains 

 a translation of Huyghens's treatise, and an ajDplication of his princi- 

 ples to the determination of the advantage of the banker at pharaon, 

 hazard, and other games, and to some questions relating to lotteries. 



A similar statement is made by Galloway in his Treatise on 

 Prohahility, page 5. 



79. It does not appear however that there was any fellow 

 of the Royal Society named Motte; for the name does not occur 



