144 ON THE OEIGIN OF THE PLANETAEY SYSTEM. 



circumstances as to the past, and as to the future, 

 imperatively lead to an impossible state of things; 

 that is, to the necessity of an infraction of natural 

 laws, of a beginning which could not have been due 

 to processes known to us. Hence, to begin such an 

 investigation as to the possible or probable primeval 

 history of our present world, is, considered as a ques- 

 tion of science, no idle speculation, but a question as 

 to the limits of its methods, and as to the extent to 

 which existing laws are valid. 



It may perhaps appear rash that we, restricted as 

 we are, in the circle of our observations in space, by our 

 position on this little earth, which is but as a grain of 

 dust in our milky way ; and limited in time by the 

 short duration of the human race; that we should 

 attempt to apply the laws which we have deduced 

 from the confined circle of facts open to us, to the 

 whole range of infinite space, and of time from 

 everlasting to everlasting. But all our thought and 

 our action, in the greatest as well as in the least, 

 is based on our confidence in the unchangeable order 

 of nature, and this confidence has hitherto been the 

 more justified, the deeper we have penetrated into the 

 interconnections of natural phenomena. And that the 

 general laws, which we have found, also hold for the 

 most distant vistas of space, has acquired strong actual 

 confirmation during the past half-century. 



