ON THE METHOD OF ZADIG. 



experience, the effects. If a written history can be pro- 

 duced otherwise than by human agency, or if the man 

 who wrote a given document was actuated by other than 

 ordinary human motives, such documents are of no more 

 evidential value than so many arabesques. 



Archaeology, which takes up the thread of history 

 beyond the point at which documentary evidence fails 

 us, could have no existence, except for our well-grounded 

 confidence that monuments and works of art or artifice, 

 have never been produced by causes different in kind 

 from those to which they now owe their origin. And 

 geology, which traces back the course of history beyond 

 the Kmits of archaeology, could tell us nothing except 

 for the assumption that, millions of years ago, water, 

 heat, gravitation, friction, animal and vegetable life, 

 caused effects of the same kind as they do now. Nay, 

 even physical astronomy, in so far as it takes us back 

 to the uttermost point of time which palastiological sci- 

 ence can reach, is founded upon the same assumption. 

 If the law of gravitation ever failed to be true, even 

 to the smallest extent, for that period, the calculations 

 of the astronomer have no application. 



The power of prediction, of prospective prophecy, is 

 that which is commonly regarded as the great preroga- 

 tive of physical science. And truly it is a wonderful 

 fact that one can go into a shop and buy for small price 

 a book, the " Nautical Almanac," which will foretell the 

 exact position to be occupied by one of Jupiter's moons 

 six months hence; nay more, that, if it were worth 



