THEORT of the EARTH, 273 



BUT, if it were neceflary always to fee this immediate con- 

 nection, in order to acknowledge the operation of a power 

 which, at prefent, is extinguifhed in the effect, we fhould lofc 

 the benefit of fcience, or general principles, from whence parti- 

 culars may be deduced, and we fhould be able to reafon no bet- 

 ter than the brute. Man is made for fcience ; he reafons from 

 effects to caufes, and from caufes to effects ; but he does not 

 always reafon without error. In reafoning, therefore, from ap- 

 pearances which are particular, care muft be taken how we ge- 

 neralize ; we Ihould be cautious not to attribute to nature, laws 

 which may perhaps be only of our own invention. 



THE immediate queftion now before us is not, if the fubter- 

 raneous fire, or elevating power, which we perceive fometimes 

 as operating with fuch energy, be the confolidating caufe of 

 ftrata formed at the bottom of the fea ; nor, if that power be 

 the means of making land appear above the general furface of 

 the water ; for, though this be the end we want to arrive at ul- 

 timately, the queftion at prefent in agitation refpects the laws of 

 nature, or the generality of particular appearances. 



HAS the globe within it fuch an active power as fits it for 

 the renovation of that part of its conftitution which may be 

 fubject to decay ? Are thofe powerful operations of fire, or fub- 

 terraneous heat, which fo often have filled us with terror and 

 aftonifhment, to be confidered as having always been ? Are 

 they to be concluded as proper to every part upon the globe, 

 and as continual in the fyftem of this earth ? If thefe points in 

 queftion mall be decided in the affirmative, we can be at no 

 lofs in afcertaining the power which has confolidated ftrata, nor 

 in explaining the prefent fituation of thofe bodies, which had 

 their origin at the bottom of the fea. This, therefore, fhould 

 be the object of our purfuit ; and, in order to have demonftra- 

 tion in a cafe of phyfical enquiry, we muft again have recourfe 

 to the book of nature. 



M m THE 



