406 SIR CHARLES LYELL 



form laws of change. The same assemblage of general 

 causes, they conceive, may have been sufficient to produce, 

 by their various combinations, the endless diversity of effects, 

 of which the shell of the earth has preserved the memorials ; 

 and, consistently with these principles, the recurrence of an- 

 alogous changes is expected by them in time to come. 



Whether we coincide or not in this doctrine we must 

 admit that the gradual progress of opinion concerning the 

 succession of phenomena in very remote eras, resembles, in 

 a singular manner, that which has accompanied the grow- 

 ing intelligence of every people, in regard to the economy of 

 nature in their own times. In an early state of advancement, 

 when a greater number of natural appearances are unintel- 

 ligible, an eclipse, an earthquake, a flood, or the approach 

 of a comet, with many other occurrences afterwards found 

 to belong to the regular course of events, are regarded as 

 prodigies. The same delusion prevails as to moral phenom- 

 ena, and many of these are ascribed to the intervention 

 of demons, ghosts, witches, and other immaterial and super- 

 natural agents. By degrees, many of the enigmas of the 

 moral and physical world are explained, and, instead of 

 being due to extrinsic and irregular causes, they are found 

 to depend on fixed and invariable laws. The philosopher at 

 last becomes convinced of the undeviating uniformity of 

 secondary causes; and, guided by his faith in this principle, 

 he determines the probability of accounts transmitted to him 

 of former occurrences, and often rejects the fabulous tales of 

 former times, on the ground of their being irreconcilable 

 with the experience of more enlightened ages. 



Prepossessions in regard to the duration of past time. As 

 a belief in the want of conformity in the cause by which 

 the earth's crust has been modified in ancient and modern 

 periods was, for a long time, universally prevalent, and that, 

 too, amongst men who were convinced that the order of na- 

 ture had been uniform for the last several thousand years, 

 every circumstance which could have influenced their minds 

 and given an undue bias to their opinions deserves particular 

 attention. Now the reader may easily satisfy himself, that, 

 however undeviating the course of nature may have been 

 from the earliest epochs, it was impossible for the first cul- 



