SIR CHARLES LYELL 223 



organic, if we fail to perceive that such is not the plan of Nature. 



I shall now conclude the discussion of a question with which we 

 have been occupied since the beginning of the fifth chapter — namely, 

 whether there has been any interruption, from the remotest periods, 

 of one uniform and continuous system of change in the animate and 

 inanimate world. We were induced to enter into that inquiry by 

 reflecting how much the progress of opinion in Geology had been 

 influenced by the assumption that the analogy was slight in kind, 

 and still more slight in degree, between the causes which produced 

 the former revolutions of the globe, and those now in every-day opera- 

 tion. It appeared clear that the earlier geologists had not only a 

 scanty acquaintance with existing changes, but were singularly un- 

 conscious of the amount of their ignorance. With the presumption 

 naturally inspired by this unconsciousness, they had no hesitation in 

 deciding at once that time could never enable the existing powers of 

 nature to work out changes of great magnitude, still less such im- 

 portant revolutions as those which are brought to light by Geology. 

 They therefore felt themselves at liberty to indulge their imaginations 

 in guessing at what might be, rather than inquiring what is ; in other 

 words, they employed themselves in conjecturing what might have 

 been the course of Nature at a remote period, rather than in the 

 investigation of what was the course of Nature in their own times. 



It appeared to them far more philosophical to speculate on the pos- 

 sibilities of the past, than patiently to explore the realities of the pres- 

 ent ; and having invented theories under the influences of such maxims, 

 they were consistently unwilling to test their validity by the criterion 

 of their accordance with the ordinary operations of Nature. On the 

 contrary, the claims of each new hypothesis to credibility appeared 

 enhanced by the great contrast, in kind or intensity, of the causes re- 

 ferred to and those now in operation. 



Never was there a dogma more calculated to foster indolence, and 

 to blunt the keen edge of curiosity, than this assumption of the dis- 

 cordance between the ancient and existing causes of change. It pro- 

 duced a state of mind unfavourable in the highest degree to the candid 

 reception of the evidence of those minute but incessant alterations 

 which every part of the earth's surface is undergoing, and by which 

 the condition of its living inhabitants is continually made to vary. 

 The student, instead of being encouraged with the hope of interpret- 



