750 SCIENTIFIC THOUGHT. 



occupied by the great thinkers who governed and 

 revolutionised the thought of earlier generations before 

 the great generalisations of science, notably those con- 

 nected with the ideas of energy and the theory of descent, 

 could have had any influence whatever. Though the 

 latter have acquired in recent times a great, perhaps 

 an undue, importance, it will only be after becoming 

 acquainted with an earlier and different phase of philo- 

 sophic thought that we shall have once more to return 

 to those conceptions and trains of reasoning which must 

 be uppermost in the mind of the writer as well as of the 

 reader of the foregoing chapters. 

 5. But in starting on the historical account of an en- 



The geo- 

 graphical tirely different realm of thought, I shall not only have 



centre of J J 



hou g s ht hic to ask my readers to enter into a new circle of ideas, 

 which for a long time during the course of the nineteenth 

 century lay entirely outside of that circle of ideas with 

 which we have become acquainted so far ; we shall be 

 assisted also by finding an entirely different geographical 

 centre from which these ideas emanated. It has been 

 repeatedly pointed out that the great volume of scientific 

 thought with which we have hitherto been occupied, 

 emanated in the latter part of the eighteenth century 

 from the French capital ; and in the course of narration 

 I have had to go back almost in every single instance 

 to the foundations laid in French scientific literature. 

 I shall now have to invite my readers to give their 

 attention to the peculiar features which were charac- 

 teristic not of French but of German literature at 

 the end of the eighteenth and the beginning of the 

 nineteenth century, 



