472 GENERAL REFLECTIONS ON 



word hypotheses thus applied to all of these theories must 

 not startle, for it is unquestionably true that no opinion 

 has yet been advanced, or perhaps ever can be advanced, 

 on the nature of the distinction between man and the brute, 

 that does not involve some open or concealed assumption 

 of what it is impossible for us to prove. The merits of the 

 hvpothesis must rest entirely on the probability of this as- 

 sumption, and the following classification shall not there- 

 fore be according to the order of time in which these the- 

 ories have been started, but as nearly as possible according 

 to the apparent probability of the assumptions they involve. 

 As this plan will show the connexion which exists between 

 these several opinions, every shade of them that has been or 

 may be formed, will more easily be comprehended. 



It were needless to enumerate every obstacle that im- 

 pedes our progress in this branch of Natural History. There 

 are a few, however, which must not escape us ; of which 

 the chief indubitably is, that little, except the fact of its fu- 

 ture immortality, having been positively revealed to us on 

 the physical qualities of the sentient principle, w T e find ma- 

 terialists and immaterialists with equal zeal applying scrip- 

 tural texts to the support of the most opposite doctrines. 

 We ought also to take into consideration the fact that the 

 majority of our ideas, even those of reflection, are during 

 this life in some measure dependent upon the influence ex- 

 ercised by matter on our material organs. Hence it be- 

 comes peculiarly difficult for immaterialists to preserve 

 their ideas of spirit and matter separate. The purity of the 

 one is generally contaminated by certain lurking notions, 

 which little analysis of our thoughts soon convinces us 

 to have been derived from the other. Another prominent 

 difficulty is, mat, whatever be the nature of the sentient 



