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complicated. We conclude for inflance that in a certain cafe 

 the confideration of pecuniary intereft has had a certain influence 

 on the mind, becaufe no other motive appeared in that inftance 

 to be prefent to the mind, and we could fcarcely miflake in 

 attributing the effed to the Jingle caufe with which it appeared 

 to have connedion. In like manner we conclude that the hopes 

 of credit or power, and the defire of gratifying paflion, produce 

 certain tendencies, and that different ftates of mind difpofe men 

 varioufly with regard to the reception of truth. It were eafy 

 to feled from the facred writings examples of fuch cafes. 

 This peculiarity in the operation of moral caufes appears to give 

 confiderable force to conclufions concerning their influence in 

 particular cafes, and to balance any difadvantage which might 

 arife from our inability to determine the queftion of their necef- 

 fary operation. If we could afcertain that moral caufes ad 

 necefl!arily, this fuccefllve nature of the operations of the mind 

 might perhaps in fome cafes, not too much complicated, enable 

 us to arrive at certainty ; but as I conceive that this queflion 

 is beyond the limits even of probable conjedure, I conclude that 

 the credit of teftimony can never rife above probability. Our 

 ignorance of the nature of all caufes, moral as well as phyfical, 

 mufl: banifli Arid and abfolute certainty from every enquiry into 

 the material or intelledual world. 



I HAVE now finiflied what I propofed ; and if it fhall appear 

 that I have more accurately defcribed the nature and boundaries 

 of certainty and probability, and diftinguiflied both from that 

 region into which the human mind is unable to penetrate, I 



VoL.V. F f ' fliall 



