GEOLOGICAL SCIENCE. 



distant times, have produced analogous effects ; whether 

 they are capable of explaining the appearances which 

 meet our view. Hence the investigation of secon- 

 dary causes becomes inevitable; and hence geological 

 theories become inseparable from geological appear- 

 ances. The laws which govern the phenomena of na- 

 ture, force themselves irresistibly on our attention. 

 They are strictly involved with the analogies which 

 regulate all our reasonings and direct our observations ; 

 and, without them, we cannot proceed a step on firm 

 ground. They distinguish the philosopher from the 

 empiric; and combine scattered observations into a 

 body of useful and rational science. Even in the 

 science of Nature, as in that of numbers, the assump- 

 tion of imaginary or erroneous laws, leads to the dis- 

 covery of the true. The history of astronomy is, in 

 itself, a lesson to those who ignorantly undervalue the 

 pursuit of general laws* Bewildered in spheres and 

 vortices, it arose, as in a moment, complete, from the 

 theory of gravitation. 



Hence the consideration of secondary causes forms, 

 not only a legitimate, but an essential part of geolo- 

 gical science. That science, like all others, comprises 

 the history of all the facts which it involves; and, 

 from these, it establishes certain general analogies. 

 Ascending a step higher, it declares the laws which 

 have regulated, and will continue to regulate, all the 

 phenomena of the globe; and thus finally establishes 

 a legitimate theory of the Earth. 



But a work of this extent, involving such an ex- 

 tensive series of phenomena, cannot soon be perfected. 

 It may not yet have been even sketched; since, of the 

 truth of those schemes which have been proposed, 

 we can have no valid evidence but that arising from 



