238 THE TWO FLORAS, 



Fpe^tators of such an event, we would not believe our owu 

 eyes till we had scrupulously examined all the circumstances, 

 and assured ourselves that there was no trick or deception. 

 After such an examination, we would not hesitate to admit 

 it, notwithstanding its great improbability ; and no one would 

 have recourse to an inversion of the laws of vision in order 

 to account for it." Kow, here is the principle broadly laid 

 down, that it is impossible to communicate by the evidence 

 of testimony, belief in an event which might happen, and 

 which, if it happened, ought on certain conditions to be credit- 

 ed. No one knew better than La Place himself, that the 

 possihility of the event which he instanced could be repre- 

 sented with the utmost exactitude by figures. The proba- 

 bility, in throwing a single die, that the ace will be presented 

 on its upper face, is as one in six, — six being the entire num- 

 ber of sides which the cube can possibly present, and the 

 side with the ace being one of these, — the probability that 

 in throwing a pair of dice the aces of both will be at once 

 presented on their upper faces is as one in thirty-six, as against 

 the one sixth chance of the ace being presented by the one, 

 there are also six chances that the ace of the other should 

 not concur with it ; and in throwing three dice, the proba- 

 bility that their three aces should be at once presented is, of 

 course, on the same principle, as one in six times thirtv-six, 

 or, in other words, as one in two hundred and sixteen. And 

 thus, in ascertaining the exact degree of probability of the 

 hundred aces at once turning up, we have to go on multi- 

 plying by six, for each die we add to the number, the pro- 

 duct of the immediately previous calculation. Unquestion- 

 ably, the number of chances against, thus balanced with the 

 single chance ybr, would be very great ; but its existence as 

 a definite number would establish, with all the force of arith- 

 metical demonstratton, the possibility/ of the event ; and if an 

 eternity were to be devoted to the throwiiyj into the air of 



