154? STUDY OF NATURAL HISTORY. 



of being ; and it therefore follows that only one ot 

 the opinions just glanced at can be true. Now, if 

 we are unacquainted with any general laws of 

 animal variation, by which the soundness of con- 

 flicting inferences can be tested, how are we to 

 decide in the case before us ? It is clearly impos- 

 sible: each opinion is supported by reasons, and 

 each party appeals to and acknowledges the very 

 same facts. In the infancy of science, such questions 

 were generally decided by the authority and the in- 

 fluence of a name. As knowledge increased, such 

 arbitrary authorities also multiplied; but their in- 

 fluences proportionally declined. Each, however, 

 still continues to have its little circle of disciples, 

 who, from having studied under, and imbibed the 

 system and opinions of, their master, tenaciously 

 adhere to what they have been taught to consider as 

 truth. 



(94.) Here, then, lies that species of prejudice 

 against which we would more especially caution the 

 student ; and which, if he will not conquer it, will 

 incapacitate him, both from rising to the present 

 level of science, and from extending its boundaries. 

 He should ever bear in remembrance, that facts, 

 authenticated by the experience of others, or falling 

 under his own cognisance, are immutable, because 

 nature is ever the same; but that the inferences 

 from them may be so numerous, and so contradictory, 

 that, until we are acquainted with some general laws 

 whereby universal agreements can be established, 

 one inference, in point of fact, is just as good as 

 another. To illustrate our meaning more plainly, 

 let us look to four of the greatest authorities on the 



