126 HUME V 



and it is conceivable that these may at first exist, 

 without any power of reproducing them, as 

 memories; and, consequently, without ideation. 

 Still higher, an apparatus of correlation may be 

 superadded, until, as all these organs become more 

 developed, the condition of the highest speechless 

 animals is attained. 



It is a remarkable example of Hume's sagacity 

 that he perceived the importance of a branch of 

 science which, even now, can hardly be said to 

 exist ; and that, in a remarkable passage, he 

 sketches in bold outlines the chief features of 

 comparative psychology. 



"... any theory, by which we explain the operations of the 

 understanding, or the origin and connection of the passions in 

 man, will acquire additional authority if we find that the same 

 theory is requisite to explain the same phenomena in all other 

 animals. We shall make trial of this with regard to the hypo- 

 thesis by which we have, in the foregoing discourse, endeavoured 

 to account for all experimental reasonings ; and it is hoped that 

 this new point of view will serve to confirm all our former 

 observations. 



"First, it seems evident that animals, as well as men, leam 

 many things from experience, and infer that the same events 

 will always follow from the same causes. By this principle 

 they become acquainted with the more obvious properties of 

 external objects, and gradually, from their birth, treasure up a 

 knowledge of the nature of fire, water, earth, stones, heights, 

 depths, &c., and of the effects which result from their operation. 

 The ignorance and inexperience of the young are here plainly 

 distinguishable from the cunning and sagacity of the old, who 

 have learned, by long observation, to avoid what hurt them, 

 and pursue what gave ease or pleasure. A horse that has been 

 accustomed to the field, becomes acquainted with the proper 



