286 STUDY OF NATURAL HISTORY. 



analogies; — they darken the subject itself to which 

 they are applied, whilst they diffuse over it their own 

 specious colouring : hence such analogies, although 

 fictitious, may be properly used by the poet or the 

 orator, to ennoble and beautify subjects which re- 

 quire dignity and ornament ; but they cannot for a 

 moment be admitted into the precincts of physical 

 science. An instance, indeed, in ordinary cases, on 

 which a just analogy is founded, may in itself be 

 fictitious, as in the employment of parables and fables, 

 or in putting a supposed Case; yet such instances, 

 where science is out of the question, may be just 

 analogies, because they are instances of some real 

 principle obtained by previous induction, or actual 

 observations embodied in some arbitrary form. They 

 are, in fact, latent inductions, or philosophical truths 

 divested of their proper evidence. The real difference, 

 then, between an argumentative and an illustrative 

 analogy, each being considered simply as such, 

 consists in the form in which they are discerned. If 

 each of several particulars analogically compared is 

 otherwise known, and they are only brought together 

 by analogy, then they are illustrations only of each 

 other. But if certain particulars only are known, 

 and these are employed for the investigation of 

 another particular, then are the known particulars, 

 arguments to the unknown one. The process, how- 

 ever, of detecting the justness of the analogy is the 

 same in both cases. 



(197.) Analogy is in all subjects the life and soul 

 of illustration. It represents to us the same general 

 truth under different forms, and under different 

 points of view ; and this property is in itself a fruit- 

 ful source of instruction. For though the facts 



