XI.] GEOLOGICAL REFORM. 231 



from these I reason with regard to that which must 

 have been." * 



And again : — "A theory of the earth, which has for 

 object truth, can have no retrospect to that which had 

 preceded the present order of the world ; for this order 

 alone is what we have to reason upon ; and to reason 

 without data is nothing but delusion. A theory, there- 

 fore, which is limited to the actual constitution of this 

 earth cannot be allowed to proceed one step beyond the 

 present order of things." 2 



And so clear is he, that no causes beside such as are 

 now in operation are needed to account for the character 

 and disposition of the components of the crust of the 

 earth, that he says, broadly and boldly : — " . . . There 

 is no part of the earth which has not had the same 

 origin, so far as this consists in that earth being collected 

 at the bottom of the sea, and afterwards produced, 

 as land, along with masses of melted substances, by the 

 operation of mineral causes." 3 



But other influences were at work upon Hutton beside 

 those of a mind logical by Nature, and scientific by 

 sound training ; and the peculiar turn which his specu- 

 lations took seems to me to be unintelligible, unless these 

 be taken into account. The arguments of the French 

 astronomers and mathematicians, which, at the end of 

 the last century, were held to demonstrate the existence 

 of a compensating arrangement among the celestial 

 bodies, whereby ail perturbations eventually reduced 

 themselves to oscillations on each side of a mean po- 

 sition, and the stability of the solar system was secured, 

 had evidently taken strong hold of Hutton's mind. 



In those oddly constructed periods which seem to have 

 prejudiced many persons against reading his works, but 



1 The Theory of the Earth, vol. i. p. 173, note. Ibid. p. 2S1 



* Ibid. p. 371. 



